An RFID-tag fabricating apparatus for fabricating an RFID tag provided with an IC circuit, including a substrate-accommodating device for accommodating a first substrate in the form of a tape having a printable surface and a second substrate in the form of a tape to be bonded to the first substrate, a printing device operable to form a predetermined printed indicium on the printable surface of the first substrate, a tag-tape forming device operable to form a tag tape, by bonding together the first and second substrates such that a plurality of IC circuit portions are interposed between the first and second substrates, a tag-tape cutting device operable to cut the tag tape formed by the tag-tape forming device, and a tag-tape cutting control portion operable to change a length of a segment of the tag tape to be obtained as the RFID tag by cutting of the tag tape by the tag-tape cutting device, on the basis of a length of the printed indicium formed on the first substrate, and such that the segment includes at least one of the IC circuit portions, whereby the dimensions of the RFID tag can be changed depending upon the dimensions of the printed indicium formed on the first substrate.