Abstract: The present portable exterminating apparatus uses an ignite charge of gas to produce both concussion and heat within the burrow of a rodent, along with residual toxic fumes, all contributing to rodent extermination. The apparatus includes a barrel, an injection control assembly, an ignition system, and a safety system including a pressure sensor and preferably a check valve. The mixing chamber of the apparatus mixes a flammable gas, such as propane, with oxygen, preferably from a bottled oxygen source, at a desired ratio. The barrel nozzle is placed into the burrow opening, and the flammable mixture is discharged into the burrow, and subsequently ignited. The ignition system including a battery, an ignition switch, and an improved ignition component inducing arcing across a pair of electrodes located within the nozzle of the barrel. The ignition switch is preferably located near the discharge valve for one-hand operation of the apparatus.