It is difficult to say why using household eco-account books, which are said to be very effective in reducing environmental impact, is not popular today. We believe that the reason for this lies in not only the design of the books, but also the attitude of the people who use them. In order to clarify this, we analyzed the background, the attitude, and the description of the books of twenty-one people who had been using the books for more than three years. The research showed that those who had been keeping these books were generally more than sixty years old and had a lot of free time. It also showed that they could be classified into four different groups. We named them as follows: “Nonbiri” are the members who use the books casually. “Kotsukotsu” use the books on a regular basis. “Waiwai” tend to work in groups, and “Takumi” thoroughly investigate the cause and are active in environmental investment. Of these groups, the people identified as members of Waiwai and Takumi had been using the books relatively longer than the other groups, and their books showed the effect of the reduction of emissions of carbon dioxide. As a result of our research, we came to the following conclusions: (1) It is important to understand that there are two stages, reducing energy on a day to day basis and reducing CO₂ by environmental investment. (2) Book-keepers who would like to be part of “Takumi” should be identified. (3)Creating groups like “Waiwai“ should be encouraged.