PURPOSE: To eliminate the loosening of the conductor of a coil and thus improve the insulation performance by adopting a hollow terminal.

CONSTITUTION: The metallic terminal 11 in cylindrical form which has a through hole 12 has a screw thread cutting in the outer periphery except for the lower part. An angular nut 13 is fitted to this terminal from the upper end, and this nut fits to an angular reverse recess 9 formed in the lower part of an insulator terminal hole at the time of being inserted into the insulator, resulting in the prevention of the idling of the terminal. To connect the conductor of the transformer, the terminal 11 is tightened with a nut 10 and then fixed in the insulator 7 of the upper cap 6, the conductor 4 of the transformer is made to pass through the through hole 12 of the terminal 11, and thereafter the upper cap 6 is tightened to the package 1 with screws, which is capped firmly. Next, the loosening of the conductor in the package is removed by stretching the conductor projected out from the terminal upper end to the direction of the arrow mark, the top end 11 of the terminal is soldered with the conductor at the position, and the extra conductor is cut off, resulting in completion.