An engagement part fitted in an outer package of an ink cartridge is provided with: a fit-in rib which is provided at a circumferential edge on a rear side and which serves as a guide upon engagement with an opening of the outer package; an engagement rib provided upright at the circumferential edge of the engagement hole in the same direction as a direction of the fit-in rib; and a bonding region for bonding a communication tag that performs near field radio communication with a printer. A tag-removing hole which is formed in the bonding region and which is to be removed from a bonding surface side of the communication tag with a bar-like member inserted is formed in a formation region as the bonding region located in a first quadrant and a fourth quadrant in an orthogonal coordinate system.