An output device for a power tool includes an output unit, a stationary ratchet gear unit, a spring disposed between the output shaft unit and the stationary ratchet gear unit, a locking member having pawls, a case accommodating the aforementioned parts and a control device threadedly connected to the case. The output unit includes an output shaft with a first bearing and a movable ratchet gear which have movable ratchet teeth facing stationary ratchet teeth of a stationary ratchet gear. The stationary ratchet gear includes ribs and each rib has an inclined surface. When the pawls are not engaged with the ribs, the output shaft can outputs power in a form of rotation in both directions. When the pawls are engaged with the ribs, the output shaft outputs power in a form of rotation in a forward direction combined with vibration or rotation in a reverse direction without vibration.