<p>A valve body has a main body formed with an inflow channel for a first fluid, an inflow channel for a second fluid, and an outflow channel 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 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>
