To solve such a problem that, while there is a case in the process of manufacturing products of concrete or metal wherein the rough adjustment of end parts or planes is carried out by using a hand carry grinder attached with a rotary grinding wheel, while fine adjustment is performed by hand operations using the kind of a tool attached with paper abrasive, the result is that a high level of skill is required for adjustment using a hand carry grinder, and in addition, paper abrasive is heavily consumed requiring frequent replacement.

In order to solve the problem, there is provided a holder of rotary grinding wheel for manual grinding, by which the manual grinding can be performed by attaching the tool to the rotary grinding wheel.