A bearing device capable of slidably supporting a piston rod without using a guide bush to eliminate fall-off of the guide bush and an additional work such as caulking, capable of reducing the production cost, preventing leak of an oil liquid, preferably having excellent durability and causing the piston rod to smoothly slide for a long time without generating offensive sound. In a bearing device of a single cylinder hydraulic buffer equipped with seal members (55, 56, 57 and 64) and a rod guide (6) or a gas spring or a multi-cylinder type hydraulic buffer, the rod guide (6) includes a cylindrical fitting portion (13) that fits to an end portion of a cylinder (2), a cylindrical bearing portion (16) for guiding the piston rod (5) and a bearing layer (15) integrally fixed to the inner peripheral surface of the cylindrical bearing portion and coming into sliding contact with the outer periphery of the piston rod. While the bearing layer (15) is integrally fixed in advance to only a portion that serves as a portion of the cylindrical bearing portion (16) on the surface of a base material made of a thin steel sheet, the bearing device is integrally shaped into a cylindrical shape by pressing and deep drawing.