To realize a confidential printing with accurate and yet less declined efficiency when printing from upper devices such as two or more personal computers and the like is outputted.

When provided with a human body detection part 10 that detects a human body in the neighborhood of an image output device in response to a demand from upper devices for printing a confidential document, the human body detection part 10 detects the existence of a human body, but the printing output ceases until the existence of a human body is no longer detected.