According to the present invention, an endoscope valve is provided that comprises a cylinder, a cylinder liner, a piston, and a sleeve. The cylinder has a groove on a lateral surface of the cylinder. The cylinder liner has a cylindrical shape and is inserted into an inner circumference of the cylinder. The piston is inserted into an inner circumference of the cylinder liner. The sleeve has a sleeve rib, a sleeve skirt, and a pin. The sleeve rib covers at least part of an open end of the cylinder. The sleeve skirt covers at least part of a circumferential surface of the open end. The pin projects from the sleeve skirt towards the circumferential surface to engage with the groove. The cylinder liner has a rib that projects radially outward from a circumference of the cylinder liner. The sleeve rib holds the rib on the open end in the case that the pin engages with the groove.