To reduce cost by reducing the number of springs for holding a main spool and a sub-spool in a neutral position, when constituting a position feedback mechanism for correcting a positional error in the main spool, by using the sub-spool movably fitted in the axial direction to both end parts in the axial direction of the main spool.

A neutral position holding mechanism 63 is constituted by using a first spring receiving member 25 stored in a pilot chamber 22, a second spring receiving member 26 movably fitted in the axial direction around the base end side of a sub-spool projection part 7a, a third spring receiving member 27 fixed to a projecting tip part of the sub-spool projection part 7a, a spring 18 for the main spool interposed between the first spring receiving member 25 and an anti-body side surface part 22a of the pilot chamber 22, and a spring 20 for the sub-spool interposed between the second spring receiving member 26 and the third spring receiving member 27.