To facilitate exchange of a suction and discharge valve device for high pressure pump.

A valve device for a high pressure pump is held in a proper position by a plug with a screw and provided with a holder having a valve plate and a valve seat, and a threaded shank 14 having an annular groove 15 for a seal gasket making contact with the inner wall of a cavity having a threaded plug to retain a valve device. An annular groove to receive a seal gasket 16 is positioned adjacently to the end part of a screw positioned in the vicinity of the valve device and inserted in a plug containing cavity having diameter lower than the outside diameter of the screw of a plug.