A heat exchanger (30) includes vertically arranged flat tubes (33) and plate-like fins (36) arranged in the direction in which the flat tubes (33) extend. The flat tubes (33) are inserted into notches (45) of the fins (36). Parts of the fins (36) between vertically adjacent ones of the notches (45) are windward plate parts (70), and parts of the fins (36) at leeward sides of the notches (45) are leeward plate parts (75). Each of the windward plate parts (70) includes windward heat transfer promotion parts (71) constituted by protrusions (81-83) and louvers (50a, 50b). On the plate parts (75), leeward heat transfer promotion parts (76) constituted by leeward protrusions (84) are provided. The heat transfer promotion parts (76) are located at leeward sides of the notches (45), and overlap with the heat transfer promotion parts (71) when viewed from front edges (38) of the fins (36).