WATCHING Young Frankenstein, Mel Brooks's newest movie, is like being tickled to death for two hours. In some places it works and in some places it doesn't, but when it does you're absolutely helpless. Brooks's style is characteristically high-pitched and hypertense, but his mocking glance is actually so loving and his techniques often so predictable and familiar that the effect is surprisingly soothing. This is a good movie to see when you're washed out, overworked, and don't want to think anymore. This is a good movie to see this month.

Brooks went back to the '30s ostensibly looking for a sci-fi classic to spoof, and got carried away. At first he appears to be parodying the original Dr. Frankenstein, made forty years ago. In fact, he takes his original material quite seriously and treats it with respect. He has to; he's not only getting story, structure and characters gratis, but he's getting a perfect medium for parody of a much broader scope. Dr. Frankenstein was a first, a great film, which provoked a rash of science fiction movies over the next decade or so that decreased in merit as the form became increasingly stylized. Brooks pokes fun, although only randomly and superficially, at an era's worth of cinematic convention, parodying the bathos and pretentious moralizing of the sci-fi genre (from scientist-as-god to man-as-monster), aping its character stereotypes, and blatantly stealing bits from famous artists of the period.

Gene Wilder, who co-wrote the screenplay, plays the wild-eyed, wild-haired grandson of the Baron von Frankenstein in a brilliant, highly personal take-off on the familiar character of the mad genius. He begins the movie as an American neurosurgeon frantically embarrassed by his ancestor's antiscientific shenanigans. Forced to journey to Transylvania to receive the Baron's will, he discovers the ancient laboratory and is seduced by his grandfather's dreams--providing the set-up for a spoof of every major scene in the original film, interrupted by the tangents of Brooks's imagination and concluded by a resounding coda. Wilder alternates moments of deadpan lucidity with the sudden spasms of pure manic fury that characterize the egotist/neurotic. He turns ordinary comic ineptitude into a thoroughly debilitating frenzy that intensifies as the dire experiment proceeds; the riotous heights of the film are all his.

Other characters are the stereotypes of science fiction stories deliberately overturned. The lab assistant, usually a mousily intelligent character who worships the Professor from afar, is here the dumbest blonde on film and never wears a lab coat. Because she has a heart of gold and sleeps with the Doctor without making a big fuss, she gets her man. Dr. Frankenstein's fiancee is gorgeous, but a fastidious prude--until she falls madly in love with the monster. The monster, hideous and despised by human society, becomes a sex symbol. Peter Boyle, as the monster, has eyes that say everything. Madeline Kahn is so luscious in the role of the fiancee that she seems even sexier with two vertical white streaks in her hair as the Bride. The lab assistant, Teri Garr, is cute and makes the most of inevitably dumb lines.

The movie is peppered with direct steals from famous stars, roles and songs, most of which originated in the '30s. The hunch-backed servant Igor (Marty Feldman) has the bulging eyes and eerie mischievousness of Harpo Marx, or of the Charles Adams cartoon character who later became known as Uncle Fester. He delivers one-liners like Groucho. Cloris Leachman, who does a terrific job of frowning and mugging through an unrewarding part, may have pilfered from Dame Judith Anderson's role in Rebecca as the forbidding keeper of the Baron's castle. Young Frankenstein stalks about with the mad intensity and even the cap and cloak of Sherlock Holmes (whose film image dates from the 1930s). "Chattanooga Choo-choo," a popular song of the '30s, resurfaces when Wilder leans out of the train window on arrival and asks, "Is this Transylvania Station?" and is answered by other lines from the same song, "Yes, this is Track 29. Would you like a shoe shine?" The movie is haunted by old ghosts--even Adolf Hitler reappears with a wooden arm and a speech impediment as the village police chief. There is much more thievery for those sharp enough--or old enough--to catch it.

BROOKS DOESN'T say much in this film but he has a good time--and so do we--and that, for him, seems to be exactly the point. The method makes this fairly clear: He has liberated himself from some of the most basic and demanding elements of film-making--story, dramatic rhythm, setting, scene structure--by co-opting the great plot of the Mary Shelley novel and faithfully copying the set design and scene sequence of the original film. He gives himself the freedom to make puns, play with sight gags, and concoct outrageously incongruent scenes--which is after all what he does best--without having to worry about the basics, which are already taken care of. This is not an altogether foolproof technique. The funniest scenes occur when Brooks leaves the real story behind and develops his own fantasies. When he is tinkering with the original scenes he tends to be over-literal and the humor becomes heavy-handed. For instance, he bungles the famous, pathetic scene in which the monster, hugging the little girl who accepted him as a friend, innocently crushes her to death. In this version the adorable child and the monster are throwing petals into a well; the cherub looks up too sweetly and asks, "What sall we twow in next?" Thud. Obvious lines fed from one character to another abound, and Brooks often repeats his favorite gags, good or bad, with little regard for the audience's tolerance. You can see a joke coming from around the bend.

Brooks's respect for his material is partly shown by his faithfulness to the original film: He has stunningly recaptured its style and its effects with black and white film, an ancient-sounding though perfectly intelligible sound track, astonishingly authentic-looking sets, and lots of dry ice on the ground. In a different way he shows even more respect for the book. The romantic writers were preoccupied with the relationship between artist and creation, and in her novel Mary Shelley explored the consequences of the creator's inability to accept responsibility for his creation. One only has to see Young Frankenstein with his arms around the monster, affectionately crooning, "This is a good boy...this is a mother's angel," to recognize that Brooks has overturned the greatest stereotype of all by putting on film what everyone has always wanted to happen. He seems to understand those of us who, as children, secretly hated the movie for being terrifying as hell. Like a kind parent, he takes the bogeys away by making it all seem hysterically funny.