The problem to be solved by the present invention is to provide a fuel injection controller capable of bringing the fuel injection amount closer to the ideal one. Solving Means We let the throttle opening at P2 be denoted by TH0. Here, P2 is a specific time later than the peak value of an intake pipe internal pressure PB of a previous cycle. In the cycle, P3 is a specific point that is set immediately before the calculation of the injection time shown by a rectangle filled with diagonal lines. We let the throttle opening at P3 be denoted by TH1. The injection amount is corrected based on a variation in correction time (ta0 to ta1). Effect Point P2 is later than point P1 as (f) in Fig. 4 . Therefore, the correction is completely unaffected or only slightly affected by the intake pipe internal pressure, if affected at all, thus ensuring close-to-ideal correction.