The finishing process is applied to a surface of a roller 8 constituting a cam follower unit by the barrel finishing. When a position of a highest portion out of fine roughnesses existing on the surface is assumed as an outermost surface position, an occupation ratio of a sectional area of a virtual plane in a plane direction at a portion that is positioned at a depth of 2.0 μm from the outermost surface position to an area of an overall surface of a portion that contacts the other member is set to 90% or more. With this configuration, a tough oil film can be formed between the surface of the roller 8 and the other member, and also the improvement of durability of a member such as the roller 8, or the like, which contacts the other member via a rolling contact or a sliding contact, can be achieved at a low cost.