GAS FUEL INJECTION VALVE

The present invention is a gas fuel injection valve, wherein in the front end surface of a valve plunger (10), a circular recessed part (51) surrounded by an annular land part (50) that serves as the outer peripheral part of the valve plunger is formed, the inner peripheral surface (51b) of the circular recessed part (51) is formed in a tapered shape in which the diameter thereof increases from the bottom surface (51a) of the circular recessed part (51) toward the annular land part (50), an annular lip (53) joined to a region extending from the inner peripheral surface (51b) to the annular land part (50) and seated on a valve seat (7) is formed in a seating member (17), and the annular lip (53) is disposed such that an annular ridge line (R) at the top thereof is located on the inner peripheral surface (51b) on the projected plane in the axial direction of the valve plunger (10). Consequently, the height of the annular lip of the seating member is lowered as much as possible to thereby prevent the bounce of the valve plunger, initial plastic deformation of the annular lip, sticking of the annular lip to the valve seat, and the like and stabilize the fuel injection quantity characteristic, and also the annular lip can satisfactorily fulfill the function of softening the valve opening impact of the valve plunger.