Abstract: In an electric hand-operated machine tool, particularly a hand-operated circular saw, with a drive spindle which is driven by an electric motor via a gear unit, a spindle locking arrangement is provided for locking the drive spindle when changing the rotary tool, and includes a slot disk provided with at least one locking slot and arranged on the drive spindle or on the power take-off shaft of the motor so as to be fixed with respect to rotation relative thereto. The spindle locking arrangement also has a locking pin which is insertable in the locking slot against the force of a restoring spring.