a core for an electromagnetic device includes a yoke and at least two legs extending from the yoke . the yoke and at least two legs are formed of steel plates laminated together . each of the legs has a free end face forming a magnetic pole face , a first groove extending from the magnetic pole face and a second magnetic groove on a side face thereof . also , the core includes a shading coil having a metal ring shape , and including a first linear section and a second linear section extending in parallel with each other . a part of the first linear section is accommodated in the first groove , and a part of the second linear section is accommodated in the second groove and locked therein . a bottom face of the second groove forms an angle with respect to a bottom face of the first groove .