PURPOSE: To eliminate the deflection of air-fuel ratio in acceleration in a purging region.

CONSTITUTION: A fuel controller is equipped with a purging means 40 for introducing the evaporated fuel generated in a fuel tank 19 into an intake passage 7 and a purge quantity detecting means 41 for detecting the introduced quantity of the evaporated fuel. Further, the fuel controller is equipped with an acceleration detecting means 42 for detecting the acceleration of an engine and an acceleration increased quantity correcting means 43 for correcting the acceleration increased quantity value according to the introduced quantity of the evaporated fuel which is detected by the purge quantity detecting means 41 in the acceleration in the state where the evaporated fuel is introduced into the intake passage 7 by the purging means 40. Accordingly, the acceleration increased quantity value is set, taking account of the reduction quantity of the introduced quantity of the evaporated fuel in acceleration.