To lengthen the life of a bearing part, to reduce the adverse effect of heat generated on the bearing part in relation to the peripheral member, to prevent corrosion of a base material for constituting the bearing part, and to improve the appearance.

At least one bearing surface of a rotational member 30 and a fixed member 32 is constituted of a lubricative resin layer 34, abrasion resistance and seizure resistance of the bearing surface are improved, a base material on the resin layer 34 side is constituted of an aluminum material having high thermal conductivity, heat generated on the bearing part is well radiated, an alumite film 33 is formed on the front surface of the aluminum material. When the film thickness is taken as y(μm) and the Vickers hardness is taken as x(Hv), (y) is set to a value less than 1, an incomplete film in which the aluminum material is partially exposed from the film 33 is eliminated, (y) is so set as to satisfy the expression of y<-(x/20)+30, generation of cracks to be generated on the film 33 in baking after resin layer film for forming the resin layer 34 is eliminated, and a good film having no partial exposition as well as no crack of the aluminum material is provided.