Air Conditioning Device

A sliding door has a door main body and door support sections supported by contact with an inner wall of a guide groove. The guide groove has a groove lacking section having a size that the door main body can be inserted therefrom. When a first one of the door support sections that is the closest to a tip end of the sliding door is located within the groove lacking section, another one of the door support sections that is located opposite from the tip end of the sliding door through the groove lacking section satisfies a relational expression of A≦90−0.2L, in which A represents a distance from the tip end to an end of the another one of the door support sections on a separated side away from the tip end, and L represents a door width of the door main body.