Head unit and liquid jetting apparatus

A liquid jetting apparatus comprising head units arranged side by side in a first direction, each of the head units including:

• nozzle chips which are arranged side by side in the first direction, each of the nozzle chips having a jetting surface and nozzles aligned in a predetermined direction parallel to the jetting surface and crossing both of the first direction and a second direction orthogonal to the first direction;
• a holder configured to hold the nozzle chips from a side opposite to the jetting surface of each of the nozzle chips;
• and
• a fixing plate to which the nozzle chips are fixed and which is arranged on a side facing the jetting surface of each of the nozzle chips,
• wherein the holder has first walls arranged in the second direction so as to sandwich the nozzle chips therebetween;
• two nozzle chips included in the nozzle chips are exposed from the holder in the first direction;
• each of the first walls has first projections formed on an end surface thereof facing the fixing plate;
• and
• the first projections make contact with the fixing plate.