A valve device is installed on a gas tank and opens and closes a gas filling passage. The valve device includes: a housing having a housing portion therein; a first check valve that is fixed to the housing and has a through hole, through which the housing portion and the filling passage communicate with each other; and a valve pressing member. The housing has a filling port, through which the outside and the housing portion communicate with each other. The housing portion contains a filter, disposed between the filling port of the housing and the through hole of a passage member, and a valve element that is moved between the filter and the filling port by the flow of gas. When the gas in the gas tank flows into the housing portion, the valve element moved toward the filling port seats on a valve seat and closes the filling port.