The Senate overwhelmingly approved Rep. Gerald R. Ford yesterday as the nation's 40th vice president.

The vote was 92-3 in favor of the Michigan Republican. All the opponents were Democrats.

House action scheduled for next week will complete congressional confirmation as required by the 25th Amendment, ratified in 1967.

The Senate vote had been scheduled just less than seven weeks after Spiro T. Agnew resigned the nation's second highest office and pleaded no contest to a single count of income tax evasion.

Two days later, President Nixon chose Ford, a 25-year-House veteran who has been the House Republican leader since 1965.

Ford, 60, has been pushed strongly for the nomination by his House Republican colleagues. A number of Democrats are likely to vote against him, however, because of his conservative voting record and some allegations he is unsuited for the vice presidency or presidency.

In What members said was probably the most searching scrutiny of any presidential nominee in history, Senate and House committees have sent hundreds of investigators looking into Ford's background and studied 2000 pages of raw FBI files.

Ford spent six days before Senate and House Panels, answering detailed questions about his financial dealings, handling of campaign funds and philosophy, winning congressional praise for openness and candor.

Members of both the Senate and House stressed that the proceedings were especially important because of the start of preliminarily impeachment proceedings in the House against Nixon.