Abstract: A fire extinguisher (100) comprises a tubular casing (110) defining a substantially sealed chamber (111) within that the chamber (111) communicates with the exterior environment by way of an aperture (112) fabricated at one end of the tubular casing (111); a solid propellant (120) stored within a first compartment (111a) of the chamber (111) and capable of being fully transformed into an aerosol, once heated to a predetermined temperature or higher, with fire extinguishing property; an igniting means (130) operative to heat and transform the solid propellant (120) upon turning on a switch (131) which is located outside the chamber (111); and a spray nozzle (140), which is a substantially flat piece tapering from one end to another forming a first (142) and a second opening (143) thereof with the second opening (143) being relatively smaller than the first opening (142), having the second opening (143) mounted onto the aperture (112) to discharge and direct the flow of the generated aerosol through a hollow pa