PURPOSE: To switch and output fluids of high pressure and low pressure supplied from a hydraulic power source.

CONSTITUTION: Casings 11 and 12 are constituted of cylinder bodies in hollow structure and have a 1st inlet port and a 2nd inlet port 1L, and 1st and 2nd inlet outlet ports 1A and 1B in their flanks. The casings have a 1st flow passage group which connect the 1st and 2nd inlet/ports and 1st and 2nd inlet/outlets ports to the hollow of the cylinder bodies, and also connects different places of the hollow parts of the cylinder bodies. A spool 3 is formed of a columnar body provided so as to be moved axially in the hollow parts of the casings, and has an annular grooved flow passage group on its outer periphery. When the spool moves in the hollow parts, the 1st inlet ports and 1st or 2nd inlet outlet ports or the 2nd inlet port and 1st inlet/outlet port are connected and the outlet port and 1st or 2nd inlet/outlet port are connected.