To form a coil which precisely generates a high magnetic field in a set direction, by connecting some of a plurality of electric circuits in series and then connecting them with an external circuit, or connecting the circuits with the external circuit without connecting them in series.

Terminals A9 and B0 for independent connection are connected by using connection wirings (A9-B0) between terminals for independent connection. Scroll coils Al-A8 and scroll coils B1-B8 are connected in series. A terminal A0 for independent connection and a terminal A0' for series connection are connected by using connection wirings (A0-A0') between terminals for independent-series connection. A terminal B9 for independent connection and a terminal B9' for series connection are connected by using connection wirings (B9-B9') between terminals for independent-series connection. When power is supplied between the terminals A0' and B9' for series connection, the scroll coils A1-A8 and B1-B8 are connected in series, and power is supplied. Thereby a small-sized coil which generates a large magnetic field in a set direction with high precision is obtained.