To provide an impulse extinguish gun enabling the quantity of a fire extinguisher in a liquid chamber to be detected easily from the outside without the need to determine the quantity of the extinguisher from the weight of a gun main body, and preventing shortage of the fire extinguisher during fire extinguishing work to deal with emergency.

In an impulse fire extinguishing gun, in which the inside of a cylindrical gun main body 2 is divided by an opening/closing valve 3 to provided a gas chamber 4 at its rear end and a liquid chamber 5 at its front end to eject a fire extinguisher W in the liquid chamber 5 from the front of the gun main body 2 by means of the pressure of the gas chamber 4, the gun main body 2 is provided with a liquid quantity indicating tank 9 communicated to the liquid chamber 5 and storing part of the fire extinguisher in the liquid chamber 5. The liquid quantity indicating tank 9 is provided with a liquid quantity indicating window 10 indicating the quantity of the liquid in the liquid chamber 5.