An air conditioning apparatus, comprising: a main body having at least one air inlet and at least one air outlet each being formed at a lower part of the main body; and a heat exchanger housed inside the main body and arranged in a flow passage of air to be sucked into the main body through the air inlet and blown out to a target space through the air outlet, wherein the air outlet is formed between a heat exchanger outlet-side air duct wall (10, 110, 210, 310, 410, 510, 610) and an opposing air duct wall, which is opposed to the heat exchanger out-let-side air duct wall (10, 110, 210, 310, 410, 510, 610), and wherein a thickness L1 of the heat exchanger outlet-side air duct wall (10, 110, 210, 310, 410, 510, 610) is 0.15L2 to 0.25L2, where L2 represents an inlet width of the air outlet, characterized in that i) an upper end of the heat exchanger outlet-side air duct wall comprises, in an air outlet-side region thereof, a curved surface portion formed of a curved surface, which is convex toward an air duct side, and wherein a range L3 of the curved surface portion in a thickness direction is equal to or larger than 0.4L1, and a part of the curved surface portion, which is positioned at each end portion of the heat exchanger outlet-side air duct wall in a longitudinal direction, is larger than a part of the curved surface portion, which is positioned at a center portion of the heat exchanger outlet-side air duct wall in the longitudinal direction; or ii) a thickness L1' of the heat exchanger outlet-side air duct wall at the each end portion in the longitudinal direction is larger than the thickness L1 of the heat exchanger outlet-side air duct wall at the center portion in the longitudinal direction. a main body having at least one air inlet and at least one air outlet each being formed at a lower part of the main body; and a heat exchanger housed inside the main body and arranged in a flow passage of air to be sucked into the main body through the air inlet and blown out to a target space through the air outlet, wherein the air outlet is formed between a heat exchanger outlet-side air duct wall (10, 110, 210, 310, 410, 510, 610) and an opposing air duct wall, which is opposed to the heat exchanger out-let-side air duct wall (10, 110, 210, 310, 410, 510, 610), and wherein a thickness L1 of the heat exchanger outlet-side air duct wall (10, 110, 210, 310, 410, 510, 610) is 0.15L2 to 0.25L2, where L2 represents an inlet width of the air outlet, characterized in that i) an upper end of the heat exchanger outlet-side air duct wall comprises, in an air outlet-side region thereof, a curved surface portion formed of a curved surface, which is convex toward an air duct side, and wherein a range L3 of the curved surface portion in a thickness direction is equal to or larger than 0.4L1, and a part of the curved surface portion, which is positioned at each end portion of the heat exchanger outlet-side air duct wall in a longitudinal direction, is larger than a part of the curved surface portion, which is positioned at a center portion of the heat exchanger outlet-side air duct wall in the longitudinal direction; or ii) a thickness L1' of the heat exchanger outlet-side air duct wall at the each end portion in the longitudinal direction is larger than the thickness L1 of the heat exchanger outlet-side air duct wall at the center portion in the longitudinal direction. i) an upper end of the heat exchanger outlet-side air duct wall comprises, in an air outlet-side region thereof, a curved surface portion formed of a curved surface, which is convex toward an air duct side, and wherein a range L3 of the curved surface portion in a thickness direction is equal to or larger than 0.4L1, and a part of the curved surface portion, which is positioned at each end portion of the heat exchanger outlet-side air duct wall in a longitudinal direction, is larger than a part of the curved surface portion, which is positioned at a center portion of the heat exchanger outlet-side air duct wall in the longitudinal direction; or ii) a thickness L1' of the heat exchanger outlet-side air duct wall at the each end portion in the longitudinal direction is larger than the thickness L1 of the heat exchanger outlet-side air duct wall at the center portion in the longitudinal direction.