A plasma ignition device comprising: an ignition plug; an ignition circuit applying a high voltage to the plug to start discharge; a power supply circuit including a battery section for supplying an electric energy to a discharge space of the plug having impedance reduced by discharge start, and a charging section charging the battery section with a boosted voltage by a booster circuit, wherein the power supply circuit including: a first means 610 for stopping a boosting operation of the booster circuit when the charging section voltage is equal or higher than a first reference for high-voltage abnormality; a second means 630 for detecting the charging section abnormal voltage by comparison with a second reference for low-voltage abnormality for detecting ground to conduct a given control on the power supply circuit; a third means 600 for invalidating the control of the second means until the charging section is sufficiently charged.