To provide a machining method for a stepped shaft capable of uniformly and efficiently machining a surface of the stepped shaft.

A rod like grinding tool 1 is used, and the grinding tool 1 is provided so as to perpendicularly cross the rotating stepped shaft P. By this, a curved surface P2 and a step surface P3 of a step part of the stepped shaft P gradually changing diameters following feeding movement can be uniformly ground by the same grinding tool 1 for an outer circumferential surface P4. The grinding tool 1 is rotated, and it is fed along the surfaces of the stepped shaft P while pressing it in a rotating state. Thereby, a grinding pattern oblique to a circumferential direction is formed on the step surface P3, and a circumferential flaw can be found easily.