A hammer tacker (1), which is used to drive staples (8) into a work piece (7), comprises a handle (2) and a magazine (3). The magazine includes a magazine house (4) and a magazine rail (5) which rail is connected to the magazine in such a way that it in its front end (6) can be moved in to and out of (P) the magazine house. Staples stored in the magazine are fed, by a feeding device (24) arranged in the magazine, to an outlet opening (25) in the front end of the magazine. A driver blade (10) housed in the magazine and constituting part of a driver (9) drives the staple fed to the outlet opening into the work piece. The driver (9) is attached to the magazine (3) on the magazine's outer side (19) to facilitate changing the driver blade.