The present invention provides an inductance coil comprising a magnetic core and a coil, wherein the coil is formed by winding a flat wire, and the flat surface of the wire is perpendicular to the axis around which the coil is wound. The coil is wrapped with an insulating adhesive tape and the tape is wound on the wire around an axis which is substantially in line with the direction along which the wire forming the coil extends, so as to form an isolation layer on the surface of the coil. Additionally, the present invention provides an electromagnetic device including the above inductance coil.