The present invention relates to a portable information apparatus which can realize electrical power for a longer period of time. Under the condition that the suspending mode is set, when an exclusive key is manipulated, a switch monitoring circuit detects this condition and issues an interruption to the CPU. In this timing, the CPU supplies the necessary electrical power to the CD-ROM controller, CD-ROM drive and audio circuit which are required for reproduction of CD. Thereby, a CD can be reproduced under the suspending mode.