Rotary electrical connector comprises a ring-shaped outside terminal having a circular inner circumference portion, a ring-shaped inside terminal having a circular outer circumference portion, which is concentric with the inner circumference portion of the ring-shaped outside terminal; and a rotatable ring-shaped connection terminal electrically connecting the outside terminal with the inside terminal; wherein the connection terminal elastically deforms along a radial direction thereof, an outer circumference portion of the connection terminal abuting the inner circumference portion of the outside terminal and the outer circumference portion of the inside terminal.