To provide a check valve which can suppress noise generation as much as possible by preventing chattering without damaging a water stopping function entirely.

The check valve is equipped with: a cup-like valve seat which has an outflow hole on one side end surface and an inflow hole on the other side end surface; a valve body which opens/closes the outflow hole by contacting with/separating from the outflow hole from the outside of this valve seat; a valve guiding section which is arranged within the valve seat, in which the one side end surface is connected to the valve body, a collar section is formed on the other side end surface, and a plurality of valve guide outflow hole for leading hot/cold water flowed in from the inflow hole of the valve seat to the outflow hole is arranged; and a coil spring which contacts at one end with an one side end surface inner side of the valve seat, contacts at the other end with the collar of the valve guiding section, and energizes the valve body in a direction closing the outflow hole of the valve seat. Furthermore, the plural valve guide outflow holes are formed so that an operating pressure to the valve body by the hot/cold water passed through the valve guide outflow hole may be varied until the valve body is inclined.