A multi-function printer comprises: a printer engine unit having a function of switching the mode of the multi-function printer from a print mode to a power-saving mode based on predetermined conditions; a first to a third microphone arranged at intervals on the same plane; and a control section configured to determine the position of a sound source according to the difference between the moments sound sources are captured by the first to the third microphone and switch the mode of the multi-function printer from the power-saving mode to the print mode.