An information device having a control means being operable by DC power supplied from an externally connected power supply, the information device being operable in a first operating mode in which DC power is supplied to the control means and a second operating mode in which supply of DC power to the control means is interrupted, comprising: a power switch being operable by a user and having an input terminal connectable to the power supply and an output terminal, a connection state of the power switch being switchable by the user between on and off, wherein the input terminal is connected to the output terminal when the connection state is on and the input terminal and the output terminal are disconnected when the connection state is off; a smoothing capacitor comprising a first terminal being connected to the output terminal of the power switch and a second terminal being connected to ground; a switch circuit being connected to the output terminal of the power switch and being used to supply DC power to the control means and to cut off the supply of DC power to the control means; a switch control signal generator (15; 15A; 15B) comprising a latch circuit configured to receive a start latch signal input from the control means for switching the latch circuit from an unlatched state to a latched state and, at least based on the state of the latch circuit, the switch control signal generator (15; 15A; 15B) is configured to generate a switch control signal during the latched state of the latch circuit to be input to the switch circuit for cutting off supply of DC power to the control means; and an unlatch signal generating means (16; 16s) for detecting the connection state of the power switch and for outputting, when the connection state is detected to be off, an unlatch signal (VRST) to the switch control signal generator (15; 15A; 15B) for unlatching the latched state of the latch circuit; wherein the control means is configured to output the start latch signal to the switch control signal generator (15; 15A; 15B) for changing the operating mode of the information device from the first operating mode to the second operating mode; the latch circuit is configured to be switched to the unlatched state when the unlatch signal (VRST) is input to the latch circuit, wherein the switch control signal generator (15; 15A; 15B) is configured to not output the switch control signal in the unlatched state of the latch circuit; and the switch circuit is configured to be opened when the switch control signal is input, and is configured to be closed when the switch control signal is not input. a power switch being operable by a user and having an input terminal connectable to the power supply and an output terminal, a connection state of the power switch being switchable by the user between on and off, wherein the input terminal is connected to the output terminal when the connection state is on and the input terminal and the output terminal are disconnected when the connection state is off; a smoothing capacitor comprising a first terminal being connected to the output terminal of the power switch and a second terminal being connected to ground; a switch circuit being connected to the output terminal of the power switch and being used to supply DC power to the control means and to cut off the supply of DC power to the control means; a switch control signal generator (15; 15A; 15B) comprising a latch circuit configured to receive a start latch signal input from the control means for switching the latch circuit from an unlatched state to a latched state and, at least based on the state of the latch circuit, the switch control signal generator (15; 15A; 15B) is configured to generate a switch control signal during the latched state of the latch circuit to be input to the switch circuit for cutting off supply of DC power to the control means; and an unlatch signal generating means (16; 16s) for detecting the connection state of the power switch and for outputting, when the connection state is detected to be off, an unlatch signal (VRST) to the switch control signal generator (15; 15A; 15B) for unlatching the latched state of the latch circuit; wherein the control means is configured to output the start latch signal to the switch control signal generator (15; 15A; 15B) for changing the operating mode of the information device from the first operating mode to the second operating mode; the latch circuit is configured to be switched to the unlatched state when the unlatch signal (VRST) is input to the latch circuit, wherein the switch control signal generator (15; 15A; 15B) is configured to not output the switch control signal in the unlatched state of the latch circuit; and the switch circuit is configured to be opened when the switch control signal is input, and is configured to be closed when the switch control signal is not input.