To sell a device having a heat exchanger using refrigerant to facilitate management of refrigerant such as fluorocarbon gas and prevent waste of resources.

Responsible recovery management of fluorocarbon of used refrigerant becomes easy by purchasing an installed air conditioner by a purchaser 2. A dismantling company 4 dismantles the air conditioner, divides dismantled parts into reusable parts and regeneration parts, recovers them per manufacturer, and divides the same functional parts or materials so that responsible reuse after dismantling becomes possible to realize management such as reuse of limited resources. A repair company 5 can perform efficient repair using the reusable parts supplied by the dismantling company 4. Moreover, a user 1 pays use charge and is not required to take final disposal into account because he/she is not required to perform ownership management so that asset management becomes clear.