<p>A gas charging device reversely supplies fresh gas from a gas outlet (7b) of a pressure reducing valve (7) to a gas inlet (7a) thereof. A pressure reducing member (17) of the pressure reducing valve (7) has a communication passage (30) which communicates the gas outlet (7b) with an actuation chamber (29). The communication passage (30) has a peripheral wall (30a) provided in its end surface with a portion (43) to be sealed, which faces the gas outlet (7b). A charging nozzle (34) has an interior area provided with a charging passage (35) which communicates with the gas outlet (7b). A push member (37) is attached to the charging nozzle (34) and is provided with a projection (40) which sticks out toward the pressure reducing member (17). The projection (40) has a sealing means (41). The sealing means (41) is directed from the gas outlet (7b) to the actuation chamber (28) so that it comes into sealing contact with the portion (43) to be sealed. <IMAGE></p>
