An electric actuator driving and controlling device configured to drive and control an electric actuator mounted in a piece of equipment, comprising: a drive unit positioned in a first environment in the piece of equipment and configured to apply power to the electric actuator; and a control unit positioned in a second environment in the piece of equipment and configured to transmit, to the drive unit, a power command signal including information related to power to be applied to the electric actuator, wherein the electric actuator is a polyphase alternating motor or a brushless DC motor, the drive unit comprises a drive element portion configured to, based on a voltage or a current inputted, apply power to the electric actuator, and the drive element portion of the drive unit includes a plurality of switching elements corresponding to a plurality of phases of the polyphase alternating motor or the brushless DC motor; an interface portion configured to receive the power command signal and, based thereon, input a voltage or a current to the drive element portion, wherein the interface portion generates a PWM signal and inputs the PWM signal to the drive element portion, and the interface portion inputs a voltage or a current to each of the plurality of switching elements; characterized in that the first environment having the drive unit and the interface portion positioned therein is harsh compared with the second environment having the control unit positioned therein; the drive unit comprises the interface portion; the control unit transmits the power command signal to the drive unit by serial communication or optical communication; and the interface portion generates the PWM signal based on the power command signal transmitted by serial communication or optical communication from the control unit. a drive unit positioned in a first environment in the piece of equipment and configured to apply power to the electric actuator; and a control unit positioned in a second environment in the piece of equipment and configured to transmit, to the drive unit, a power command signal including information related to power to be applied to the electric actuator, wherein the electric actuator is a polyphase alternating motor or a brushless DC motor, the drive unit comprises a drive element portion configured to, based on a voltage or a current inputted, apply power to the electric actuator, and the drive element portion of the drive unit includes a plurality of switching elements corresponding to a plurality of phases of the polyphase alternating motor or the brushless DC motor; the electric actuator is a polyphase alternating motor or a brushless DC motor, the drive unit comprises a drive element portion configured to, based on a voltage or a current inputted, apply power to the electric actuator, and the drive element portion of the drive unit includes a plurality of switching elements corresponding to a plurality of phases of the polyphase alternating motor or the brushless DC motor; an interface portion configured to receive the power command signal and, based thereon, input a voltage or a current to the drive element portion, wherein the interface portion generates a PWM signal and inputs the PWM signal to the drive element portion, and the interface portion inputs a voltage or a current to each of the plurality of switching elements; the interface portion generates a PWM signal and inputs the PWM signal to the drive element portion, and the interface portion inputs a voltage or a current to each of the plurality of switching elements; characterized in that the first environment having the drive unit and the interface portion positioned therein is harsh compared with the second environment having the control unit positioned therein; the drive unit comprises the interface portion; the control unit transmits the power command signal to the drive unit by serial communication or optical communication; and the interface portion generates the PWM signal based on the power command signal transmitted by serial communication or optical communication from the control unit.