An information processing apparatus which is in enhanced in operability. A printing apparatus (information processing apparatus) operates in a normal operation mode in which normal operation is enabled, or in an energy-saving mode in which power consumption is reduced. A USB host interface communicates with a USB device. When the printing apparatus is operating in the energy-saving mode, electric power is inhibited from being supplied to the USB host interface and an energy-saving block, and a microprocessor of a system LSI causes the printing apparatus to shift from the energy-saving state to the normal operation state when the USB device is connected to the USB host interface.