The ink tank unit 122 (first material) includes ink storage tanks ST1 to ST4 for temporarily storing the respective color inks, and first pipes DP1 to DP4 respectively provided for the ink storage tanks ST1 to ST4. In the ink tank unit 122, connector receivers JM1 to JM4, which are male-type connectors of the same shape, and respectively attached to one end of the four first pipes DP1 to DP4, are aligned on a predetermined location. In FIG. 3, the four connector receivers JM1 to JM4 are linearly aligned in a row. On the predetermined location, name plates indicating the type of the first pipes DP1 to DP4, or the ink colors yellow (Y), cyan (C), magenta (M), and black (Bk), are attached to positions respectively corresponding to the four connector receivers JM1 to JM4. The four connector receivers JM1 to JM4 may be collectively aligned in two rows in horizontal and vertical directions. The four first pipes DP1 to DP4 are respectively connected to the ink storage tanks ST1 to ST4, at the other end. Hereinafter, the connector receivers JM1 to JM4 may be unspecifically referred to as connector receiver JM.
