A heat exchanger is provided to perform heat exchange function without using a separate fin and to apply to a heater pump system for cooling and heating by reducing condensed water through the pin. A heat exchanger comprises: two header tanks; a plurality of tubes(30) consecutively arranged between two header tanks; and a refrigerant through-hole(31) formed inside the tube. Two header tanks are communicated to the refrigerant through-hole. The air is heat-exchanged with the refrigerant flowing within the tube by passing the air through intervals among a plurality of tubes. The tube is curve-cut along the passing-direction of the air and performs the heat exchange without a separate folding fin.
