The machine tool according to the with a pneumatic hammer mechanism comprises a motorized exciter, a guiding tube, and a piston-shaped beater. The piston-shaped beater is guided by an interior surface of the guiding tube along an operating axis and with the exciter encloses an air spring in a guiding tube. The beater shows a cup-shaped basic body with an open hollow space facing the exciter and an inset filling the hollow space. The basic body is made from a first material with a first density and the insert is made from a material with a second density, which is lower than the first density.