To provide a fluid control valve which maintains a sealing property of a valve element and prevents operation failure of an opening and closing valve.

The fluid control valve has: a valve main body 13 with a valve seat 20; a diaphragm valve body 27 for controlling a fluid flow by contacting with or departing from the valve seat 20 of the valve main body 13; a piston 22 connected to the diaphragm valve element 27 and movable in a shaft direction; a knob 14 for operating an action of the piston 22; and a resin cover member provided with the knob 14, for pinching the diaphragm valve element 27 with the valve main body 13 and enclosing the piston 22. The fluid control valve also has an attachment member bracket 15 provided with: a cover fixing position 15b to be fixed at an end part in a shaft direction of a cover member: and an external fixing position 15c to be fixed at outside of the fluid control valve.