LCA (life cycle assessment) is known as one of the techniques for assessing reasonable use of energy considering environment. Usefulness of LCA was examined by checking the consistency between the assessment result on refrigerators by LCA and ISO standards. LCA can digitize the data on energy substances, wastes and emission of the whole system. LCA is useful for effective use and control of resources, and to clarify the reduction chance of environmental impacts. However, the framework is necessary to estimate the accuracy of assessment technique for every category, and the reliability of influence assessment. Like a risk assessment for environmental damages, identification of discharge sources beyond the assessment function of potentials is difficult. As the viewpoint of the whole life cycle is important, assessment of local damages is difficult. The complementary use of LCA and other tools about sustainable development is important. The comparison result between ISO provisions and this LCA case study showed that this concrete research report can play a role as text book for the ISO technique. 74 refs., 38 figs., 45 tabs.