An electronic device includes a circuit board including at least one electronic component, a housing accommodating the circuit board, an emissivity control layer disposed in an upper portion of the circuit board and transmitting radiant heat generated by the electronic component, and a temperature controller controlling an amount of the radiant heat transmitted to the housing by adjusting the emissivity of the emissivity control layer. The temperature controller may adjust the emissivity of the emissivity control layer to a first range value, when the electronic device is in an idle state, not performing a foreground operation, and may adjust the emissivity of the emissivity control layer to a second range value, lower than the first range value, when the electronic device is in a busy state, performing the foreground operation.