A CPU that has transferred to a stop mode in order to reduce power consumption can be restarted from a control section of a printer, but cannot be restarted by an instruction from a host computer. The printer according to the present invention includes an interface control section for communicating with the host computer; a CPU having a mode in which the CPU is on standby in a low power consumption state; and a clock control section supplying a clock signal. The clock control section supplies a clock signal only to the interface control section when the CPU transfers to the stop mode.