To provide an actuator that can flexibly and softly move like muscles, can maintain a stable operation over a long period of time, can generate a strong driving force, has a rapid input response, has a favorable sensitivity, has a high energy conversion efficiency, and can be accurately controlled. A coil is embedded in a magnetic elastomer obtained by mixing a powder-like ferromagnetic or highly magnetic permeable material with an elastomer, so that the coil can be electrically connected. By electrically connecting the coil, a magnetic field generates in the coil and around the coil. The magnetic field penetrates the magnetic elastomer. When the magnetic field generates in the magnetic elastomer, deformation force acts on the magnetic elastomer by the magnetic force acting on each portion in the magnetic elastomer. Thus, driving force can be obtained.
