A lighting apparatus is comprised of an illumination unit arranged so as to project from a light apparatus body by a predetermined distance, a spring for spring-biasing the illumination unit in the direction in which the illumination unit is projected from the light apparatus body, a power switch for the illumination unit which is switched in accordance with a movement of the illumination unit, an engaging portion for engaging the illumination unit at the position close to the light apparatus body, and a releasing portion for releasing the engaging portion, wherein the lighting apparatus can be energized only when the illumination unit is projected from the lighting apparatus body. Also, an electrode apparatus attached to power source equipments such as a battery pack or the like is comprised of an electrode cover for shielding an electrode portion, wherein the electrode cover can be opened by a projected electrode portion of the equipments to which the power source equipment is attached.