To provide a fire extinguisher which enables the actuation thereof even by a tiny flame while allowing the spreading of the extinguishing material thoroughly into a garbage can in a wider range.

The fire extinguisher has a through hole 5 corresponding to a garbage inlet 3 when it is installed on the garbage can 1 having a garbage inlet 3 at the upper part thereof and has as a body thereof a bag body 8 which enables to store water 6 and air 7 therein. At least one side of the bag body 8 is formed of a cellophane, a resin film or a resin-based emulsion or latex 12 while the water 6 and the air 7 are stored therein. As a result, the part coming into contact with the air 7 is torn quickly in a wider range by a flame 13 to cause the water 6 to be sprayed into the garbage can 1 thereby achieving the quick extinguishment of the fire without manned monitoring.