PURPOSE: To improve sensitivity by forming primary coils and secondary coils with a film pattern, and by passing a core through a through-hole at the center of a glass substrate.

CONSTITUTION: A through-hole 11a is provided at the center of a glass substrate 11. On the other hand, primary coils 13a, 13b are formed on both sides of the glass substrate 11 in a film pattern, and electrodes 13c, 13d are provided on the ends of the glass substrate 11. Then, secondary coils 15a, 15c are laminated on the primary coils 13a, 13b through an insulating film layer 14a. Secondary coils 15a, 15b are laminated on the primary coils 13a, 13b through an insulating film layer 14b, and then are covered by an insulating film layer 14c. At this time, the secondary coils 15a, 15b are connected through a connecting terminal 15e. Next, a core formed with magnetic substance is passed through the through- hole 11a of the glass substrate 11. As a result, sensibility and minimum resolution performance can be improved.