To provide a buried type gas plug improving each operating performance opening/closing a cover unit and releasing a socket.

This device comprises a gas plug main unit 1 having a gas plug part 13 buried in a wall or floor and an opening 14 for making from outside the wall or floor a socket 7 able to be mounted/demounted in the gas plug part 13, cover unit 2 supported able to turn so as to open/close the opening 14 and placed in an attitude extended to an inward side from the opening 14 in an opened condition, slide member 3 mounted able to slide relating to the cover unit 2 so as to make a press-in possible in the inward side from outside the wall or floor in an opened condition, and a lever member 4 turned by the press-in of the slide member 3 in the opened condition with a support point part 51 provided in the gas plug main unit 1 serving as the center to press a tip end surface of the socket 7 mounted in the gas plug part 13.