A problem with conventional article management systems has been that the management scheme for articles. The present invention addresses this problem by providing an article management system comprising: a transmitting antenna for transmitting a radio signal; a receiving antenna for receiving a radio signal; a article to be managed positioning region whereat articles to be managed are placed; an RF tag provided with a tag transmitting unit which electromagnetically couples with the transmitting antenna and the receiving antenna; and an RFID reader which sends a transmission signal to the RF tag via the transmitting antenna and receives a response signal outputted by the tag transmitting unit via the receiving antenna. The RFID reader detects whether or not a article to be managed is present by detecting for changes in the operation characteristics of the tag transmitting unit due to the article to be managed according to changes in either the strength or phase of the response signal from the RF tag.