PURPOSE: To provide a camshaft formed at a low machining cost by forming the eccentric cam part in the camshaft of a non-eccentric shaft and a bearing with an eccentric inner wheel.

CONSTITUTION: A shaft 1 is of stepped shape formed of a large diameter part 1a and a small diameter part 1b, and the small diameter part 1b is cut at its upper face so as to be formed into D-shape cross section. A bearing 2 to be fitted to the small diameter part 1b is formed of an inner wheel, an outer wheel and a needle provided between both the wheels. The inner wheel is provided with a D-shape through hole for fitting the small diameter part 1b of the shaft 1. This D-shape through hole provided in the inner wheel is formed being decentered by from the center of the inner wheel.