Monitoring system of person coming to entrance comprises camera for capturing image of the person and recorder for the captured image, the system informing the person of the image recordation for deterring a crime in bad visit case or making polite notice in goodwill visit case. Unlock system has an intercom for visitor to request unlock and a self unlock operating portion for resident. If unlock done through intercom with acquaintance confirmed, polite notice is preferred, whereas “note record” is added to the image record in case of intercom unlock with unacquainted assumed. If unlock done by resident, the information and the image recordation are withheld. If entrance in a group detected, “note record” is added to the image record in case bad person successively follows goodwill person duly unlocking entrance. Privacy of acquaintance visitor image is protected by password. “Note record” is added to image record without voice message.