An electronic device includes a main body and a thermoelectric conversion module. The main body has a heat generating element therein. The thermoelectric conversion module includes a shell and a thermoelectric conversion element. The shell is assembled to the main body. The thermoelectric conversion element is pivoted on the shell and has an operation surface and a back surface opposite to each other. The thermoelectric conversion element is adapted to rotate between a first state and a second state relatively to the shell. When the thermoelectric conversion element is in the first state, the operation surface faces the main body and receives heat from the heat generating element, for the thermoelectric conversion element to generate electricity. When the thermoelectric conversion element is in the second state, the back surface faces the main body and the operation surface receives heat from external environment, for the thermoelectric conversion element to generate electricity.