An electric hammer comprising a hammer bit (313) performing hammering work on a work, a drive motor, a hammering piece (334) driven by the drive motor to apply a hammering force to the hammer bit, and a mechanism (371) for damping vibration generated during hammering. The damping performance of the electric hammer is enhanced by causing the driving amount applied to the damping mechanism (371) to vary between a first mode where the damping mechanism (371) generates vibration of the hammer bit (313) subjected to an external force from the work during the load driving time and thereby optimizes the damping and a second mode where the damping mechanism (371) generates vibration corresponding to the vibration of the hammer bit (313) not subjected to an external force from the work during the no-land driving time and optimizes damping.