We have proposed a thermally regenerative fuel cell operated by low-temperature thermal energy such as solar thermal energy and low-temperature waste heat. It consists of the chemical reaction of 2-propanol dehydrogenation at the negative electrode and the acetone hydrogenation at the positive electrode by using the principle of a fuel cell. As the first step of this research, we investigated the acetone hydrogenation. Activity of ruthenium and platinum composite catalyst (3 wt.%) supported on a carbon plate for the reaction was much higher than that of ruthenium catalyst or platinum catalyst at 90 degreesC. Activity of ruthenium and platinum composite catalyst was much higher when it was supported on carbon felt or cloth than a plate. We adopted ruthenium and platinum composite catalyst supported on carbon cloth as electrodes of the cell and examined its characteristics. First, we used molecular hydrogen instead of 2-propanol as a proton source. Under this condition, the open-circuit voltage and the short-circuit current were 104.6 mV and 8.98 mA, respectively. As loading of the catalyst became higher, the short-circuit current also became larger. The short-circuit currents were 11.5 and 26.7 mA when loading of the catalyst was 5 and 30 wt.%, respectively. Then we used 2-propanol as a proton source. We investigated effects of 2-propanol concentration, catalyst loading and reaction temperature on the cell efficiency. When 2-propanol was diluted with water and supplied to the negative electrode, it was shown that 2-propanol concentration of 50-70 vol% was the best for cell efficiency. The cell efficiency was improved with increasing catalyst loading. As for reaction temperature, 80 degreesC was better to improve the efficiency.