A vehicle air conditioner includes an air conditioning case having an air introducing port from which air is introduced in an air introducing direction from a side of a cooling heat exchanger to a space under the cooling heat exchanger. Further, the air conditioning case includes a flow turning portion by which air introduced from the air introducing port is turned and flows through the cooling heat exchanger upwardly, and the cooling heat exchanger is slanted to have an upper end portion and a lower end portion approximately parallel to the air introducing direction. Furthermore, a plate member is arranged in the air conditioning case at a position under the lower end portion of the cooling heat exchanger, and the plate member has a plate surface which crosses with the air introducing direction to reduce a flow speed of air.