A gas inlet (4), a stop value (7), a pressure reducing valve (8) and a gas outlet (5) are arranged in series within a valve casing (3). The gas outlet (5) and an outlet (7b) of said stop valve (7) are communicated with each other by a gas charging passage (10) provided with a check valve (11). The gas outlet (5) is communicated with a secondary safety valve (28) by a gas inducting passage (29). When a gas cylinder (1) is charged with a gas, a gas charging mouthpiece (14) is attached to the gas outlet (5). Thereupon, an opening or closing portion (A) provided in the gas inducting passage (29) is closed by an actuating portion (30) provided in the mouthpiece (14). Thereby, a high-pressure gas is not released from the secondary safety valve (28).