PURPOSE: To standardize the electromagnetic coil structure for every core type and to contrive accomplishment of highly efficient production by a method wherein metal pieces with a projection, to be used for mounting of a printed wiring board, are unmovably arranged in a plastic case in such a manner that they are not come in contact with one another.

CONSTITUTION: The objective electromagnetic coil is equipped with a toroidal- shaped magnetic core having a non-saturated or saturated iron core 1, a plastic case 4 with which said toroidal-shaped iron core is covered, metal pieces 2 constituting a part of a winding, and a printed wiring board 4 with which the metal pieces are formed in coil shape. The metal pieces 2 are fixed without coming into contact with one another, and they are formed in such a manner that the toroidal magnetic core is surrounded by them. Accordingly, the metal pieces 2 can be formed into small pieces to the pitch practicable with the printed wiring board. As a result, the number of turns of the winding against the electromagnetic coil on the printed wiring board can be controlled freely, the structure of the electromagnetic coil for each core shape can be standardized, and the efficiency of production can be improved.