A coil 31 has 1st to Nth turns 311 to 31N. The 1st to Nth turns 311 to 31N are respectively provided with actuation parts 311a for current in one direction to flow, and connection parts 311b for current in the opposite direction to the one direction to flow. The plurality of actuation parts 311a are arranged substantially parallel to each other, and are arranged along a surface of an object 1 or a surface that approximates to the surface of the object 1. A plurality of connection parts 311b are arranged within a space in which the connection parts do not face the surface of the object 1 over the actuation parts 311a of the 1st to Nth turns, and the connection parts are positioned at the sides with respect to the extension direction of the actuation parts 311a.
