To provide a tool, especially pruning shears having a simple structure, producible at a low cost, applying an extremely small load on the casing in pruning work and, accordingly, enabling the use of a casing having a simple and easily handleable form.

This pruning shears 1 have a pair of relatively movable blades 11, 12. A blade 11 is fixed to a casing 2 and the other blade 12 is driven by a motor 5 through a screw spindle 8, a nut 21 attached to the screw spindle and a rod connected to the nut. The blade 11 is provided with an extension piece 13 extended to the inside of the casing 2 and the screw spindle 8 is rotatably supported by a rolling bearing 31 which is fixed to the screw spindle 8 and supported especially in the axial direction in the notch 17 formed on the extension piece 13.