To provide a power tool that achieves inexpensive and easy integration of split cores of a stator in an electric motor.

The power tool includes an electric motor having a stator formed by winding a coil around a core, and a rotor rotatably arranged inside the stator. The stator core is divided so as to form a plurality of split cores 2b3. A plurality of core pieces are laminated so that a step is provided for each sizable dimension in the lamination thickness direction at each division boundary part. A protruding part 2b4 and a recessed part 2b5 are formed at the division boundary part of each split core 2b3. A locking piece 10 protruding in the lamination thickness direction and a locking groove 11 for storing the locking piece 10 of the split core 2b3 on the mating side are formed respectively at the protruding part 2b4 and at the recessed part 2b5 of each split core 2b3. The protruding parts 2b4 and the recessed parts 2b5 of the split cores 2b3 are suitable for each other. The locking piece 10 formed at each protruding part 2b4 and the locking piece formed at each recessed part 2b5 are respectively locked to the locking groove 11 formed at each protruding part 2b4 on the mating side and to the locking groove formed at each recessed part 2b5 on the mating side so as to join and integrate both split cores 2b3 with each other.