TRANSFORMER

The present invention is to improve a performance of a transformer having wound iron cores. The transformer having the wound iron cores which have multi-layer band-shape magnetic material, and a coil wound to pass through an inner circumference of the wound iron core, includes a wound iron core holding member that is a member longer than a width of the wound iron core for supporting an upper inner portion of the wound iron core, a coil holding member for supporting a lower outer portion of the coil, a first support structure including an upper beam arranged on an outer circumference of the wound iron core to support the wound iron core holding member, and a lower beam arranged on an outer circumference of the coil to support the coil holding member, and a second support structure including a pair of outer plates arranged on an inner portion of the upper frame and connected to a connection member that is longer than a width obtained by adding a diameter of the wound iron core and a diameter of the coil, and a wound iron core protection structure that is longer than a width of the wound iron core, for covering a portion where the outer circumference of the coil and an inner portion of the wound iron core face each other, and being connected to the outer plates.