PURPOSE: To improve productivity of a shaft provided with an oil passage having a plurality of oil holes spaced in the axial direction on the outer circumferential part and a communicating passage to communicate the respective oil holes, and to easily obtain a shaft having many kinds of oil passages.

CONSTITUTION: A first shaft element having bottomed cylindrical main bodies 11, 12 and an oil groove extended in the radial direction on the opening edge part, and a second shaft element having bottomed cylindrical main bodies 15, 16, 17, are respectively formed by forging. The first shaft element and the second shaft element are coaxially welded together by friction welding at respective opening edge parts to form a hollow shaft. Hereby, the oil groove on the opening edge part of the first shaft element is blockaded to become an oil hole 18b. Next, the outer circumferential face of the hollow shaft is cuttingly machined flatly and smoothly, and further oil holes 19, 20 are drilled.