PURPOSE: To provide a fuel supply controller for internal combustion engine with supercharger which can improve drivability and reduce harmful discharged gas component by prohibiting accelerating increment and so on resulting from the excessive measurement with an air flow sensor at the time of deceleration.

CONSTITUTION: ECU 50, when a throttle valve 9 is fully opened and such decelerating operation as a bypass valve 42 is opened with cooling water temperature TW higher than a prescribed value TWA starts, computes fuel injection time TINJ without making any accelerating increment over a prescribed time TS2 after an idling switch is changed from OFF to ON to drive a fuel injection valve 3. When the idling switch is changed from ON to OFF or the prescribed time TS2 has passed even with ON maintained, an accelerating increment is permitted. After an accelerating increment Tacc is searched from mapping based on the time changing rate ΔA/N of an intake amount, fuel injection time TINJ is computed to drive the fuel injection valve 3.