To provide a noise-cut transformer which has a transformer structure suited to miniaturization and a highly accurate noise-cut transformer function.

This noise-cut transformer comprises an internal iron core 21 made of cross magnetic plates (non-oriented silicon plate) are laminated, and an external iron core 22 that primary coils 23a and 23b fixed in the vertical part of the internal iron core 21, secondary coils 24a and 24b fixed in the horizontal part thereof, and magnetic plates (non-oriented silicon plate) are assembled in the vertical and horizontal directions of the internal iron core 21 and they are laminated.