A cam follower apparatus includes at least a roller and a supporting shaft for supporting the roller freely rotatably. Unevenness is formed equally on the surface of at least one of the roller and supporting shaft by corrosion by manganese phosphate salt and the manganese phosphate salt film is formed on the corroded surface. Good-quality oil film can be formed stably without interruption thereof under even a strict working condition with a small amount of lubricant due to the unevenness formed on the film. Therefore, direct contact between metals is prevented, thereby improving lubricity.