To efficiently and properly extinguish a fire without using a large amount of water, and reduce damages due to fire fighting activities.

When a fire fighting device 2 mounted on the ladder 1a of a fire engine 1 is carried to a position near the window of a room on a fire, a pair of CCD cameras photograph the exterior wall of a building, and calculate a distance and a direction to the window of the room on a fire on the basis of a photographed image. Thereafter, a calculation is made about a trajectory on the basis of the result of the calculation of the distance and direction, and a discharge direction and acceleration are thereby determined. Then, the fire fighting device 2 projects the predetermined number of fire extinguishing balls B toward the window. Thus, the fire extinguishing balls B are properly thrown to the room on a fire and self-blast. Fire extinguishers contained in the balls B are thereby dispersed evenly in the room.