To provide a processing degree adjusting tool not constituting obstacle in cases where boring, thread cutting, etc. is made with a processing tool, where the processing tool of the apparatus body is to be replaced with another, and where there is no need to adjust the processing degree in boring, thread cutting, etc. particularly.

A tight attachment part 1a with the side face Ta of the processing tool T is formed nearer the rear of the body 1 having a through hole H, and a set screw 2 is provided to work to the tight attachment part 1a, and in the front part of the body 1, an abutting piece 3 for the surface Wa to be processed of a work W is provided. A diametric enlarged part 1b is formed between the rear and front of the body 1, and in this part 1b, an exhaust hole 4 for chips generated from processing is provided in such a way as to be open in one part of the side face of the body 1.