Air-conditioning unit

An air-conditioning unit comprising:

• an air-conditioning case in which an air passage is formed, the air passage allowing air to flow through the air passage;
• and
• a heat exchanger disposed in the air passage and configured to perform heat exchange between a refrigerant and the air flowing through the air passage,
• wherein:
• the heat exchanger includes a plurality of tubes stacked in a tube stacking direction, extending in a tube longitudinal direction, and allowing the refrigerant to flow through the tubes, and a header tank extending in the tube stacking direction and connected to one end of each of the plurality of tubes;
• the header tank includes a tank outer wall that separates an internal space of the header tank from the outside of the header tank and extends in the tube stacking direction;
• the air-conditioning case includes a holder in which the header tank is held while being inserted in the holder;
• the holder includes a first rib and a plurality of second ribs, the first and second ribs pressing the tank outer wall toward the internal space;
• the first rib extends in the tube stacking direction;
• the plurality of second ribs are each connected to the first rib, extend from the first rib away from the tubes, and are arranged side by side at a predetermined inter-rib spacing in the tube stacking direction;
• and
• the inter-rib spacing is larger than a length of the second ribs extending from the first rib away from the tubes in the tube longitudinal direction.