An electric actuator that is composed of an AC servomotor, a base, ball screw, belt, and linear guide. This electric actuator is a general purpose robot that can be used in a wide variety of applications, such as assembly and inspection. The electric actuator utilizes highly rigid ball screw and guide, and uses resolver with excellent environment resistance for the position detector. So, it features long service life. This greatly contributes to reduction of the customer maintenance control costs.