A fire extinguisher including a body extending along a longitudinal axis and defining a storage chamber wherein a load of an extinguishing agent is present, and also a pressurizing chamber including a pyrotechnic gas generator, the pressurizing chamber being separated from the storage chamber by a perforated wall configured to put an outlet of the pyrotechnic gas generator into communication with the storage chamber, the perforated wall defining an end of the storage chamber, the extinguisher having a discharge channel configured to deliver the extinguishing agent to the outside of the extinguisher during actuation of the pyrotechnic gas generator, the discharge channel opening out into the storage chamber through an opening positioned at a distance from the perforated wall, as measured along the longitudinal axis of the body, that is less than or equal to half the length of the storage chamber.