There is provided a pedestrian protection air bag system M1 in which air bags accommodated on a cowl each have a recessed portion which avoids a hinge mechanism and project from lateral side edges of a lower surface of a hood panel at a rear end thereof so as to cover front sides of front pillars. The hood panel is configured to be raised on a rear end side thereof so as to form a projection space for the air bags between the cowl and the rear end of the hood panel, while when in normal use, the hood panel is made to be opened upwards at a front end side thereof by means of the hinge mechanisms provided near the left and right edges at the rear end thereof. The hinge mechanisms, cases which cover the folded air bags and actuators for raising the hood panel are provided sequentially in that order towards the front on the lateral side edge of the hood panel at the rear end thereof.