A drive mechanism for an electric nailer comprises a power source, an electromagnetic coil, a control unit and moving member, which are disposed in a housing. The power source provides the electromagnetic coil and the control unit with DC power at predetermined voltage, so as to enable them to generate electromagnetic force. The control unit serves to control the output of the DC power source at a standard reference potential, so that the control unit is capable of turning on the electromagnetic coils at any time points.