To more efficiently execute a system using an IC tag without embedding an IC tag in an existing apparatus plug.

The IC tag adapter includes: plug blade slots where plug blades of the apparatus plug are inserted; the IC tag in which information is written; and adapter blades each having a shape corresponding to the plug blade of the apparatus plug, to be inserted into the plug blade slot of a power supply tap. A power supply tap device includes the IC tag adapters and the power supply tap, and the power supply tap includes plug blade slots for the IC tag adapters and IC tag readers. When the adapter blades of the IC tag adapter are inserted in the plug blade slots of the power supply tap while the plug blades of the apparatus plug are installed in the plug blade slots of the IC tag adapter, information written in the IC tag of the IC tag adapter can be read by the IC tag reader.