Abstract: An electric actuator including a gear motor (1), a tubular body (3) containing a piston (2), and a connection of the motor to the piston. The piston consists of a tube (2) slidable within the body. The motor (1) is housed within the piston and secured to an end flange (4) thereof, and the output shaft (8) of the motor rotates a plug (9) provided with a screw thread (11) meshed with a complementary thread (12) on the inner wall of the body (3). As the gear motor (1) is housed within the tubular piston (2), the actuator is exceptionally compact and quiet, and the problem of the buckling of threaded rods in conventional actuators is avoided since said rods have been replaced by a tubular piston (2). Furthermore, this arrangement makes the actuator easy to seal.