The instrument has a holder part (11), esp. with a shaft (12) and handle (13) and a head (10) with a tool (7). The shaft contains a drive, esp. a thrust rod, between the handle and tool. There is a fast separating coupling between the handle and tool for changing the head or the head and part of the shaft. The storage device is a magazine (8) with several plug-in holders (9) for instrument heads (10) and connected shaft pieces in some cases. Coupling device between the holders and heads or shafts can be operated with one hand for securing the heads by operating the rapid separation coupling.
