To provide an extrusion apparatus for a hot melt adhesive capable of enhancing workability, keeping the cost and reducing the quantity of waste by smoothly applying the hot melt adhesive always heated to a proper temperature even if the extrusion apparatus is used while freely moved on a job site.

The extrusion apparatus consists of a heat-resistant resin pack filled with the hot melt adhesive, a cartridge comprising a metallic cylindrical body in which the resin pack is inserted, a preheating adaptor for heating the hot melt adhesive in the cartridge to a temperature capable of keeping a adhesive state and a gun-shaped extruder for inserting the cartridge heated by the preheating adaptor in the cylinder of which the heating state can be kept by the supply of a current and extruding the hot melt adhesive filled into the resin pack in the cartridge from the rear part of the cartridge to continuously extrude the same toward a coating surface from a nozzle.