To facilitate installation of a valve guide by molding in one piece a cylindrical synthetic-plastic valve guide, which guides a valve through its movement, with a pair of stainless-steel support members protruded from the outer periphery of the valve guide, and providing a groove in the inner periphery of a valve case in which the support members fit.

A jet pump 100 uses a vacuum generated by sending spurts of water at high speed through a jet water sending pipe 102 to draw water in through a strainer 116 and sends it via a throat tube 112. A valve case 10 made of casting is made into a cylinder and a valve 12 is disposed inside a hollow portion 10a. A valve guide 14 guides the valve 12 at it opens and closes. The valve guide 14 comprises a guide main body 16 made of synthetic plastic and a pair of support members 18, 18 made of stainless steel that protrude from both sides of the guide main body. The support members 18 are fitted into a groove 24 formed in the inner periphery portion of the hollow portion 10a, thus securing the valve guide 14 to the inside of the valve case 10.