In a heat exchange device, a plate-shaped tube (4) in which a plurality of channels (10) through which a first or second thermal medium (2), (3) flows are formed is disposed in a thermal storage material (5) that exchanges heat with the first or second thermal medium (2), (3), and the plate-shaped tube (4) is formed by joining two plates into a laminated form. Each plate has a plurality of elongated projections (8A, 9A) that protrude away from the mating faces of the plates and have hollows formed therein, and a plurality of flat portions (8B, 9B) between the projections. Openings of the hollows formed in one of the plates are closed by the corresponding flat portions of the other plate so that the hollows provide the channels.