Sealing Device

An object of the present invention is to provide a sealing device capable of maintaining a satisfactory sealing performance between a valve stem seal and a valve stem guide without separation of the valve stem seal even under a high port pressure, the valve stem seal being provided separately from a spring retaining portion. There is provided a sealing device in which a spring retaining portion (30) of a valve spring (40) is provided separately from a valve stem seal (7), the valve stem seal including a cylindrical metallic ring (1), a rubber-elastic seal lip (2) sealing a valve stem and provided in one end of the metallic ring while sliding on the valve stem, and sealing-fitting means (6) sealing an outer peripheral surface of a valve stem guide (5) provided in the inner peripheral side of the metallic ring while being fitted to the outer peripheral surface, wherein the sealing-fitting means includes a metallic fitting portion (61) in which the metallic ring directly contacts the outer peripheral surface of the valve stem guide, and a rubber-elastic rubber fitting portion (62) which is integrally retained in the inner peripheral surface of the metallic ring so as to contact the outer peripheral surface of the valve stem guide.