Abstract: A hand-held fastening element driving tool comprising a body accommodating a reciprocating actuator. The body carries a barrel wherein a striker is movable. The barrel holds a fastening element magazine. The striker consists of two parts closely fitted to each other. One part is a rectangular member whose cross-section follows the contour of a staple-shaped fastening element. The other member, together with the rectangular member, forms a figure circumscribing the head of a stem-shaped fastening element. The barrel cross-section is made as to suit the shape of the striker.