To provide a fire extinguishing device for building or institution pro vided with ordinary or emergency power generating equipment.

Since the building or institution provided with an engine driven generator 1 is provided with introducing routes 5-0, 5-1, 5-2 and 5-3 for guiding exhaust gas discharged from the engine driven generator 1 to fire extinguishing zones from 4-1 to 4-3 and the exhaust gas is guided through the exhaust gas introduction routes 5-0, 5-1, 5-2 and 5-3 to the fire extinguishing zones from 4-1 to 4-3 at the time of fire, the stock vessel for fire extinguishing agent or a water tank can be omitted and since the exhaust gas of the engine driven generator 1 is utilized, the exhaust gas as the fire extinguishing agent can be stably provided while the engine driven generation 1 is operated.