A low-pressure delivery pipe (160) provided with intake manifold injectors (120), a fuel pressure regulator (170), a high-pressure fuel pump (155), a high-pressure delivery pipe (130) provided with in-cylinder injectors (110), and an electromagnetic relief valve (210) are connected in series at the downstream of a low-pressure fuel pump (180) that discharges a fuel within a fuel tank (200) at a prescribed pressure. Since the low-pressure delivery pipe (160) is arranged downstream of the low-pressure fuel pump (180), the fuel pressure within the low-pressure delivery pipe (160) is lowered upon stop of vehicle operation, in response to stop of the low-pressure fuel pump (180). The fuel pressure within the high-pressure delivery pipe (130) is also lowered in response to stop of the low-pressure fuel pump (180), by opening the electromagnetic relief valve (210) upon stop of vehicle operation. Thus, oil tightness of the injectors (110, 120) during the stop of vehicle operation is ensured.