The instrument is assembled of a stationary (4) and a movable handle (5) attached to a shaft (2) accommodating an inner shaft (3) or a cable acting on a tool exceeding the shaft (2) at the front. The tool which can be a pair of pliers or scissors is normally held in a cylindrical metal part produced on a lathe. The new design of a tool holding unit (10) is made of a sheet of stainless steel cut into the required shape, provided with lateral reinforcing ribs (23) and formed into a pipe section (9).