To prevent the hardening of an adhesive after heated and melted by the reaction with moisture in the air in an adhesive supply tank during or after finishing the coating work in the case of performing the coating work using the reactive hot melt type adhesive.

In a reactive hot melt type adhesive applying device 12 provided with the adhesive supply tank 24 for storing the reactive hot melt type adhesive and an adhesive applying port 25 for applying the adhesive on a material to be coated at the lower part thereof, an inert gas supply mechanism 34 for supplying an inert gas is provided in the adhesive supply tank 24.