Heat exchanger and method for manufacturing same

A method of manufacturing a heat exchanger in which a plurality of corrugated plate-like fins are placed in a housing in a flow direction of coolant, the method including:

• a housing forming step of forming the housing and a positioning hole for positioning the fins in place;
• a fin forming step of forming the fins;
• and
• a fin placing step of placing the fins formed in the fin forming step into the housing formed in the housing forming step,
• wherein the fin forming step includes punching out a portion of a plate-like member present between portions that will form the adjacent fins while leaving a portion that will form a connecting part and a protrusion, and folding the portions that will form the fins into a corrugated shape, and
• the fin placing step includes fitting the protrusion into the positioning hole to place the adjacent fins at a predetermined interval in a flow direction of coolant and with a predetermined offset amount in a direction perpendicular to the flow direction of coolant.