A first resilient member generates a resilient force to urge a valve portion in a valve-closing direction. A second resilient member generates a resilient force against the resilient force of the first resilient member. The resilient force of the first resilient member and the resilient force of the second resilient member are set to be balanced with each other when the valve portion is placed in a lift position that is between a full-closing position of the valve portion, in which the valve portion is seated against a valve seat to fully close a fluid passage, and a full-opening position of the valve portion, in which the valve portion is fully lifted away from the valve seat to fully open the fluid passage.