NOVELTY - Motor system includes idle control unit to stop power generation of fuel cell which is in idle operation into an idle stop mode and ending the idle stop mode to restart power generation of the fuel cell. A state detection unit detects a state of the fuel cell when the idle stop mode of the fuel cell ends. A recovery time estimation unit estimates a recovery time taken for total voltage of the fuel cell to reach voltage at the idle operation. A control unit performs a correction control for torque of the drive motor based on the recovery time estimated by the recovery time estimation unit.    USE - System for mounting on a fuel cell vehicle.    ADVANTAGE - The system provides proper control of torque of the drive motor supplied with power from the fuel cell after recovery to the idle state according to the state of the fuel cell in the idle stop state. When the driving performance is affected by the correction to reduce the increasing rate of the drive motor request torque calculated based on the estimated value of the fuel cell stack total voltage recovery time, the upper limit of the drive motor request torque is corrected to be reduced, thus preventing deterioration in the driving performance (deterioration of the acceleration performance) due to the output limitation for protection of the fuel cell stack.    DETAILED DESCRIPTION - Motor system comprises a drive motor generating a drive force using power supplied from a fuel cell. An idle control unit stops power generation of the fuel cell which is in idle operation into an idle stop mode and ending the idle stop mode to restart the power generation of the fuel cell. A state detection unit detects a state of the fuel cell when the idle stop mode of the fuel cell ends. A recovery time estimation unit estimates a recovery time taken for total voltage of the fuel cell to reach voltage at the idle operation based on the state of the fuel cell detected by the state detection unit. A control unit performs a correction control for torque of the drive motor based on the recovery time estimated by the recovery time estimation unit.