In a heat exchanger for exchanging heat between fluid such as refrigerant and air, an object of the present invention is to extend the surface area of fins while suppressing an increase in ventilation resistance, thereby improving performances of the heat exchanger. Corrugated sheet fins (70) are provided as the fins of the heat exchanger (60). The corrugated sheet fins (70) are each shaped like a corrugated sheet. The ridgeline direction of the waveform of the corrugated sheet fins (70) is orthogonal to front edges and rear edges. In the heat exchanger (60), the plurality of corrugated sheet fins (70) are arranged at constant pitches in the axial direction of the heat transfer tube (61).