PURPOSE: To provide a transformer circuit for neon tube lighting in which the gas in a neon tube is suppressed from being distributed in standing wave form with a small-sized inexpensive circuit, and the phenomenon of generating a plurality of spherical light emitting parts in the neon tube can be solved.

CONSTITUTION: A parallel body of a diode (rectifying element) 11 and a capacitor 12 is inserted in series to the secondary output side of a transformer 10 for converting the voltage from a commercial power source 5 of AC 100 V or AC 200 V to a high voltage capable of lighting a neon tube 1. Since the phenomenon of generating a plurality of spherical light emitting parts in the neon tube thus can be solved even with a high frequency voltage, and the neon tube can be beautifully lighted, this transformer circuit is suitable for light decorative neon, and extremely economic.