A control valve includes a housing, a valve body arranged in a valve chamber of the housing, and a support portion slidably supporting an outer surface of the valve body in the valve chamber. The valve body is slidable on the support portion between an open position at which an outlet port is open and a closed position at which a seat surface of the valve body closes the outlet port. The valve body includes a skin layer forming the outer surface of the valve body, and a core layer under the skin layer. The outer surface of the valve body, other than the seat surface and a slidable area, includes a core exposed portion where the core layer is exposed without being covered with the skin layer.