PURPOSE: To enable many-sided application by providing a switching element so that an oscillation drive device is connected to a tool at a first switch position to drive the tool in an oscillating manner and a rotary drive device is connected to the tool in a second switch position to rotate and drive the tool.

CONSTITUTION: A drive shaft 14 and a tool drive shaft 12 are arranged at a right angle, a tip of the tool drive shaft 12 is extended out of a casing 17 to provide a tool receive part 48, and a tool 62 is attached to a tip thereof. This tool receiving part 48 is connected to a driven pinion 26 of an oscillation transmission device in a twist-resistant manner. The oscillation drive device is provided with an oscillation element 66 connected to the tool drive shaft 12 by a pin joint 67. A switching element 30 for drive system switching is provided so that the oscillation drive device including the oscillation element 66 oscillates the drive shaft 14 and the tool drive shaft 12 with a small oscillation angle and a high oscillation frequency centered on a longitudinal axial line 13 at a first switch position 31 thereof. At a second switch position 32, the drive shaft 14 and the tool receiving part 48 are mutually connected with respect to their action due to the meshing of a drive pinion 24 with a driven gear 26.