To provide an underfloor-buried gas valve whose manufacturing cost can be reduced by reducing the number of components, and which can be easily installed.

In the underfloor-buried gas valve, a gas valve body 2 having a plug part 22 is provided on the lower side of a floor board F, and a release lever 46 and an operation button 44 are provided on the gas valve body 2 rotatably and movably up and down, respectively. By pushing the operation button 4 down and rotating the release lever 46 counterclockwise, a socket S connected to the plug part 22 is removed therefrom. A sub operation button 5 is placed on the operation button 44.