HEAT EXCHANGER

A heat exchanger excellent in heat resistance, antifreeze resistance, water resistant, and durability is provided. The heat exchanger of the present invention includes: an outer packaging member 2 provided with a heat transfer medium inlet 24 and a heat transfer medium outlet 25, the outer packaging member being configured to allow a heat transfer medium flowed to an inside of the outer packaging member from the heat transfer medium inlet 24 to pass through the inside and flow out from the heat transfer medium outlet 25. The outer packaging member 2 is made of outer packaging laminate materials L1 each including a metal heat transfer layer 51 and a resin thermal fusion layer 53 provided on one surface of the heat transfer layer 51. The outer packaging laminate materials are superimposed one on the other, the thermal fusion layers being integrally bonded along peripheral edge portions thereof. The heat transfer layer 51 and the thermal fusion layer 53 of the outer packaging laminate material L1 are laminated via an inner adhesive agent layer 52 made of an acid-modified polyolefin-based adhesive agent containing an acid-modified polyolefin-based resin.