PURPOSE: To provide a fuel filter of an improved on-vehicle mounting property by also disposing a filter in a pipe on a return side, and integrating it with a filter on a supply side.

CONSTITUTION: A filter is constituted of a filter 41 on a supply side and a filter 42 on a return side which are integrated via a partition plate 40. The filters 41, 42 on the supply and return sides are approximately symmetrical in the vertical direction. Passages 414, 424 are formed at the centers of filters elements 413, 423. Fuel flowing in the central passages is reversed so that deposit is removed by the filter elements 413, 423. Consequently the deposit, which is a high molecular component of lubricant deposited in the fuel returned from an injection pump 5, is preented from intruding into a fuel tank to block a fuel system in the case where alcohol is used as the fuel.