A wide protection range can be ensured by extending the flying distance of fire-extinguishing agent particles electrified and sprayed from a head. A water-based fire-extinguishing agent is pressurized and supplied to an electrification spray head 10 installed in a protection area A via a pipe, the jetted particles of the fire-extinguishing agent are electrified and sprayed from the electrification spray head 10. The electrification spray head mixes and sprays the fire-extinguishing agent having a comparatively small particle size included in a range from 30 μM to 200 μm by a small-particle jetting nozzle 38a and the fire-extinguishing agent having a comparatively-large particle size of 200 μm to 2000 μm by a large-particle jetting nozzle 38b, thereby carrying the group of the fire-extinguishing-agent particles having the small particle size by the air current caused by spraying the group of the fire-extinguishing-agent particles having the large particle size.