To reduce cost and labor of management of an electric power tool by sharing constitution parts other than a braking mechanism as far as possible.

The output shaft 4 of a motor 3 is divided into a leading shaft and a rear shaft 6. Two kinds of the leading shafts are provided: a first leading shaft pivotally supported by a first shaft support plate directly connected to a motor housing 2, and a second leading shaft 23 pivotally supported by a second shaft support plate 20 connected to the motor housing 2 via a cylindrical spacer 21. The second leading shaft is longer than the first leading shaft in an axial direction. The braking mechanism 25 containing a flange plate 26 fixed to the second leading shaft 23, a braking member 27 coming into contact with and separated from the flange plate 26, and a coil spring 28 which energizes the braking member 27 to the flange plate 26 side, is assembled to the second pivotally support plate 20 and second leading shaft 23. The second leading shaft 23 is connected to the rear shaft 6, and the second shaft support plate 20 and the spacer 21 are assembled between the motor housing 2 and a front housing 8. Thus, a type having the braking mechanism 25 can be selected.