A hammer drill 1 includes a barrel 2 containing a striking mechanism. The drill further includes a motor 4 with a motor shaft 6 encased in a motor accommodating chamber 19 which has an upper opening at which a baffle plate 20 is disposed. The baffle plate 20 includes a bottom portion 21 and a partition 22. The baffle plate 20 further includes a flange 23 that extends radially around the upper edge of the partition 22 except toward the front of the partition 22 with the outer edge of the flange 23 reaching the inner surface of the motor housing 3. Additionally, a generally horizontal slot 24 is formed at the front peripheral surface of the bottom portion 21 of the baffle plate 20. Moreover, a plurality of air inlets 27 are provided at the rear end of a housing handle 5 of the drill 1, whereas a plurality of air outlets 29 are provided at the bottom of the motor housing 3. When air is drawn inside the hammer drill 1 by rotation of a cooling fan 28 fitted on the motor shaft 6, the air travels through the motor 4 upstream of the motor 4 after flowing through the barrel 2 along an extension air passage 30, thus cooling the striking mechanism.