Abstract: The present invention relates to a miniature thermal-photoelectric power supply in order to equip the mobile devices, such as, laptops, mobile phones, and the like, with the power supply which is compact, lightweight but relatively large storage capacity. In miniature thermal-photoelectric power supply in accordance with the invention, a high energy level can be stored as the heat energy in a heat energy storing layer in the form of a thin chamber containing gas CO2 in critical state. When an exciting current is applied, this stored heat energy will be taken up by means of Peltier effect, thereby releasing and converting said stored energy into light during the current discharging through an inert gas layer. The light radiates on the surface of a photoelectric cell and can be absorbed and converted into electric energy.