Flip-up apparatus for hood of vehicle

At a vehicle collision, an actuator (15) lifts the vehicle hood mounted on the vehicle body by a hinge device (5) which has arms (21,23) supporting the hood rotatably to a frame member of the vehicle body and lock plates (25,27) rotatably supported on the underside of the hood to hold an active part (51) of the actuator (15). In the upward movement of the active part, it is held by the lock plates (25,27).