To provide a liquid discharging head unit for which the cable connecting constitution is simplified, and of which the miniaturization and the cost reduction can be attained, and to provide an image forming device loaded with the liquid discharging head unit.

Piezoelectric elements 12 and 12 for each row which are arranged on a supporting board 13 are respectively connected with flexible boards 18A and 18B. On respective flexible boards 18A and 18B, driving ICs (driver ICs) 19 and 19 for selectively applying a driving waveform to respective piezoelectric elements 12 are mounted. One flexible board 20 for relaying is connected with the two flexible boards 18A and 18B, and the driving ICs 19 and a control circuit board on the device main body side are connected through the flexible board 20 for relaying.