Abstract: A small space fire extinguisher includes: a tube open from one side thereof to the other side thereof and made of a synthetic resin so that a portion thereof bursts by the heat generated when a fire breaks out to allow a fire extinguishing agent accommodated therein to spout; cylindrical blocking members coupled to both sides of the tube to prevent the fire extinguishing agent accommodated in the tube from leaking to the outside; coupling members located on the outer peripheral surface of the tube, in the state where packing members are fitted to installation grooves of blocking member bodies, and then compressed thereagainst by means of a compression device; and blocking members fitted to both side ends of the tube to prevent the coupling members compressedly fixed to the outer peripheral surface of the tube to which the blocking members with the packing members are fitted.