To provide a ceramic valve which is capable of stably obtaining the excellent sliding characteristic for a long time, a difficult to generate water leakage, and extremely excellent in maintainability.
The ceramic valve 10 comprises a fixed ceramic valve element 11 and a movable ceramic valve element 12, one sliding surface 12a of the valve elements 11 and 12 is covered with a hard carbon film mainly consisting of an amorphous carbon, and the arithmetic average roughness Ra of both sliding surfaces of the fixed and movable valve elements is set to be ≤0.08 μm. The inequality V1>V2 is satisfied, where V1 is the numerical value of the Knoop hardness HK of the hard carbon film, and V2 is the numerical value of the Vickers hardness HV of a ceramic base material to form a sliding surface 11a of the mating valve element 11 having no hard carbon film.
NISHISATO YASUAKI