To rapidly and surely extinguish a fire that occurs as the result of a vehicle accident etc., inside a tunnel, without depending on humans.

A fire-extinguishing robot 1 calculates the distance to and the direction of the place where a fire has occurred, detects the direction and speed of wind at that time, and calculates a track based on those values while taking gravitational acceleration and air resistance into account, thereby determining the direction and speed of injection of a fire extinguisher. A mechanism for turning an injection nozzle up and down, a revolving mechanism, and an injection mechanism are driven to inject the fire extinguisher. As a result, the fire extinguisher injected is allowed to reach the place of the fire with precision although its track is curved under the influences of wind and gravitational acceleration.