To make use of an electronic pet, which of course conforts the owner, for crime prevention by allowing a third person to think that a real watchdog is present by reading the change of an environmental situation from a sensor and a microphone and a crime preventing camera or the like, and responding to the change with sound quality and a voice corresponding to the situation.

An instruction issued by a speaker 1 whose voice is already recognized being the owner of an electronic pet is converted into a voice signal by a microphone, and the speaker is recognized by a speaker recognizing circuit 2, and when it is confirmed that the speaker is the owner, the voice is recognized. The information is converted into an inside parameter 3, and a voice stored in a storage medium 5 is outputted with the sound volume of the parameter based on the value of the parameter 3.