PURPOSE: To continuously carry out rough machining and finishing machining and greatly improve the machining efficiency of honing by expandably installing two types of grinding wheels for rough machining and finishing machining around a holder.

CONSTITUTION: With a hone head being inserted into the hole B of a workpiece A, first, a cone 5 is moved to the shall diameter side of the taper face 9 for rough machining, an expanding part 3b is brought into contact with the taper face 9, a rough machining wheel 3 is expanded and brought into contact face to face with the hole B, and rotation and reciprocating movement is given to the hone head to carry out rough machining. After rough machining, the cone 5 is moved in the reverse direction from the previous time, the rough machining wheel 3 is contracted and a finishing wheel 4 is expended by means of a finishing taper face 10 and brought into contact face to face with the hole B, to carry out finishing by means of the rotation and the reciprocating movement of the hone head. Accordingly, the rough machining and finishing machining of the honing can be continuously carried out, greatly improving operation efficiency.