To provide a head structure of a line head type liquid discharge apparatus which can carry out printing also to a medium with a liquid discharge surface that is not a plane, and to provide a method of mounting a discharge head of the line head type liquid discharge apparatus.

The head structure of the line head type liquid discharge apparatus which collectively discharges a liquid corresponding to data of one line to the medium to be a liquid discharge object is equipped with head modules 10 in which discharge holes to discharge the liquid are arranged linearly, and a head support 20 which has a fixing surface 21 and fixes connecting the head modules 10. A plurality of the head modules 10 are connected along the fixing surface 21 and fixed to the head support while both sides in an arrangement direction of the discharge holes are butted against each other.