To reduce power loss to an irreducible minimum of a demand, made to flow through a switching circuit which turns on/off a power supply by supply ing a plurality of loads corresponding to operating modes with power, and also to reduce the circuit mounting area.

Load is supplied with power in response to a plurality of operating modes in the electronic device, and the electronic device has at least a power supply section 36, such as an on/off controllable DC/DC converter outputting fixed DC power, a first switching circuit 38 installed onto a power supply line from the power supply section 36 to a first load 30, the second switching circuit 40 mounted on a power supply line to the second load 32 branched from the input side of the first switching circuit 38, and a control circuit 40 which on/off controls the power supply section, the first switching circuit 38 and the second switching circuit 40, in response to the operating modes.