To solve the problems such as increase in the number of parts, securing of space for a substrate, and increase in cost, which still exist even though a phase distortion is lessened by adding an externally installed condenser to a flyback transformer.

In this flyback transformer, a ceramic split resistor and a film condenser which are adjacent in parallel with each other are arranged, so that the phase distortion of split voltage of the ceramic split resistor that detects the fluctuations of high voltage becomes almost zero, by decreasing the distribution capacity that generates on the opposed face of the ceramic split resistor and the film condenser which are adjacent in parallel with each other.