A power-supply control device includes a power-supply control section, a first detection section that detects whether or not a body capable of movement is moving, a second detection section that detects whether or not the body capable of movement exists, and an instruction section. The power-supply control section receives supply of power from a mains power source section, and selectively sets a power supply mode, in which power is supplied to a processing section, and a power saving mode, in which supply of power to the processing section is stopped. The first and second detection sections and the instruction section are caused to operate at least in the power saving mode. The instruction section provides, for the power-supply control section, an instruction for switching between the power supply mode and the power saving mode.