PURPOSE: To keep lower partial voltage applied when surge voltage is applied by a method wherein the number of windings per layer in the first or ending several layers of windings of a high tension coil is reduced to one-third or less of the number of windings in its middle layers.

CONSTITUTION: The number of windings per layer in the first up to third layers of windigs of a high tension coil 4 is reduced to one-third or less of the number of windings in the fourth layer and thereafter and copper wires for the coil with the same diameter as that of those used for the fourth layer and thereafter but with width less than that for the latter are wound. Moreover, the number of windings per layer in the last up to third from the last is reduced to one-third or less of the number of windings in the fourth before the last and thereinbefore and copper wires for the coil with the same diameter as that of those used for the fourth layer and thereinbefore but with width less than that for the latter are wound. By this, static capacitance of the first up to third layers or the last up to third layers before the last of windings is made greater than that of middle layers, so that partial voltage in the first or last portion of the windings can be reduced when surge voltage is applied thereto.