To resolve a problem that, although electricity is conventionally used as energy and recently used for information communication by a computer or the like and becomes important more than ever due to IT development, since generation of a leakage current resulting from an insulation failure in a circuit causes occurrence of electric fires and electrical shock accidents, or since large accidents in an IT system such as breakdown of electrical equipment such as a lamp fitting or the like, uncontrollability of a computer, loss of unrecorded data and the like may occur due to sudden power supply interruption or the like, thus power supply should be interrupted for measurement of an insulation failure current value by an insulating resistance system and measurement in a conductive state is impossible in a conventional I0 current breaking device, and resolve a problem that an excessive inrush current is generated at the start-up of a current flowing in an electrical equipment, which gives troubles in use equipment in a circuit conventionally.

An IGR leakage breaking device is provided with an IGR-method leakage breaker to protect equipment.