An electronic device (1) includes a power supply unit (20), a to-be-used function setting unit (100), and a function-specific power supply control unit (110). The power supply unit (20) is configured to supply electric power to a constituent unit (12, 15, 16, 17, 18, 42b, 44, 45) of the electronic device (1) from a main power source. The to-be-used function setting unit (100) configured to set functions to be used when the main power source is turned on. The function-specific power supply control unit (110) configured to control the power supply unit (20) to supply electric power to a constituent unit corresponding to a function that has been set by the to-be-used function setting unit (100) when the main power source is turned on, and configured to supply electric power to a constituent unit corresponding to a function that has not been set by the to-be-used function setting unit (100) when the function that has not been set is selected after turning the main power source. The invention further relates to a corresponding method for controlling power supply.