A liquid ejecting head unit includes a head body which discharges liquid droplets; a wiring substrate which stands in a predetermined direction different from the discharging direction of the liquid from the head body in order to supply a driving signal, which drives the head body, to the head body; and a liquid flow channel unit which is disposed at a position overlapping with the wiring substrate in the predetermined direction, is integrally combined with the head body so that the flow channel is in direct communication with the head body, and includes a pressure chamber having a damper function of which at least a portion of wall surface is formed of a film member.