To reduce the resistance of a valve and prevent production of a noise in the valve for opening/closing a passage through which fluid is led to flow in a device utilizing a flow of fluid such as liquid-gas.

This valve is formed of a valve element 1, a valve seat 2 and a coil spring 3, the valve seat 2 and the coil spring 3 are arranged to be opposed to the valve element 1, and the coil pitches 10, 11 of the coil spring 3 are made to be set in plural values. Therefore, when a compressive extent is small, a load value is determined by the whole spring constants of the coil spring 3, and when the compressive extent is large, the coil pitch A10 of the coil spring 3 is tightly stuck so as to eliminate a function as a spring and the load value is determined by the spring constants of the coil pitch B11 which is not tightly stuck, thus the spring constants when the valve element 1 is actuated can be reduced greatly and the deformation of the coil spring 3 and occurrence of a noise can be prevented.