An ink cartridge including a holding member and an ink bag to accommodate ink, wherein the ink cartridge is replenished with pigment ink having a pH higher than a pH of residual ink remaining in the ink cartridge. The glass substrate is formed by using a plate-like glass produced by a float method and having a pair of main surfaces. In another embodiment, an adaptive scheme may be used to optimize threshold values based on a pre-knowledge of the noise in the channel. The inner surface of the via is covered with a first plating layer.