<p>A valve body has a main body formed with an inflow channel (61) for a first fluid, an inflow channel (63) for a second fluid, and an outflow channel (64) for the first and second fluids in common. The first fluid inflow channel is always in communication with the common outflow channel through a valve chamber. A valve element (67) operates to bring the second fluid inflow channel into or out of communication with the first fluid inflow channel and the common outflow channel.</p>
