In an in-tank valve, a detector including a detecting sensor is disposed on an end of a body, and the detecting sensor is accommodated inside a sensor housing. Within the sensor housing, a sensor retaining member is formed in an interior part of an opened sensor accommodating section, and the detecting sensor is disposed therein so as to face toward a first communication hole of the sensor retaining member. Lead wires, which are connected to the detecting sensor, are led out to the exterior in a bending fashion from a wiring port, whereby entry of hydrogen gas to the side of the detecting sensor is prevented by suitably closing the wiring port.