To carry out LCA in ISO-14040, inventory analysis (IA) is the basic. For studying arrangement of public data to carry out IA, collection work was done of background data which are indirectly concerned with copying machine. First, methods to make inventory data (ID) which are thinkable in the present situation were prepared, and items of emitted matters to be collected were set up in relation to the impact assessment method. Secondly, scenarios of each stage of life cycle of copying machine were set up, and virtual data on the material/energy consumption amount were arranged. Based on this, a method was further studied for making ID of the parts used in electric power, iron/steel, plastics, and copying machine. Third, based on the above-mentioned study results, ID was actually made, and a possibility was studied of making inventory in life cycle of copying machine. Moreover, the state of the automobile LCA carried out at Stuttgart University was examined. At last, the paper summed up subjects of and future study methods for the inventory making method. 2 refs., 25 figs., 77 tabs.