An accelerator pedal system includes a pedal lever, a lock mechanism, an actuator, and an ECU. The pedal lever operates according to a step-on operation. The lock mechanism can restrict the operation of the pedal lever. The actuator switches between a locked state in which the operation of the pedal lever is restricted by the lock mechanism and an unlocked state in which the operation of the pedal lever is not restricted. The ECU include a lock operation determination unit and an actuator control unit. The lock operation determination unit determines switching of the lock/unlock operation by the lock mechanism, in response to a voice instruction of a driver. The actuator control unit controls a drive of the actuator according to a determination result of the lock operation determination unit.