Abstract: The invention concerns a handle-shaped tool-holder instrument comprising a drive shaft (2) for a tool (7) and capable of being slid into the instrument (1) along the longitudinal axis from the rear of the instrument to be coupled with the tool-holding part (8) in a tool-holding head (4) at the front of the instrument, said tool-holding head Z(4) being mounted angularly steerable about a fixed axis (5) at the front of the instrument, means (3?, 9) being provided to lock the steerable head (4) in any selected angular position.