When the internal combustion engine (11) is stopped, the ECU (41) controls the load torque of the alternator (34) so that the engine rotational speed (NE) coincides with the target engine rotational speed. By so doing, the ECU (41) executes stop position control in which the internal combustion engine (11) is stopped so that the crank angle θ at the time of engine stop stops within the target crank angle range. While the stop position control is being executed, the ECU (41) calculates a required load torque necessary to make the engine rotational speed (NE) coincide with the target engine rotational speed (NEtg), and then compares the required load torque with the maximum load torque of the alternator (34) at the engine rotational speed (NE) at that time. Then, when the required load torque is larger than the maximum load torque, the ECU (41) ends the stop position control.