To reduce numbers of parts and the manufacturing processes and to lower the manufacturing cost.

In a manufacturing method of a hollow cam shaft casting a pipe body 3 in the inner part, after holding the end part in a mold by bending the end part of the pipe body 3, molten metal is poured into the mold. By the manufacturing method of this cam shaft, in order to directly hold the bent end part of the pipe body 3, a supporting is unnecessary to the pipe body 3 and also, a cap for closing the end part of the pipe body 3 at the time of casting is unnecessary. Further, in the hollow cam shaft casting the pipe body 3 in the inner part, the end part of the pipe body 3 is bent.