An air conditioning device (10) is an air conditioning device (10) for a reclining seat (10) comprising a seat part (1b) and a backrest part (1a), the air conditioning device (10) comprising a ventilator and a controller (11). The ventilator is provided to at least one of the seat part (1b) and the backrest part (1a), and includes a first air flow path (A1, A2) formed inside the seat part (1b) or the backrest part (1a). The controller (11) determines a reclining state of the backrest part (1a) with respect to the seat part (1b), and controls air in the first air flow path (A1, A2) in accordance with the determined reclining state.