A driving device is adapted for use in an electric nail gun. The electric nail gun includes a supporting frame. The driving device includes a swing arm unit, a control unit and a driving unit. The swing arm unit is swingable between a standby position and a shooting position. The control unit includes a control member having a driven end portion, and an abutting end portion opposite to the driven end portion. The driving unit is for driving the driven end portion of the control member to rotate between a driving position and a non-driving position, and includes a control-member biasing resilient member disposed between the driven end portion of the control member and the supporting frame.