The invention relates to a stacked panel-shaped heat transmitter comprising a plurality of interstacked trough-shaped panels (23,24) of a first and second type forming therebetween flow channels (25,26) for a first medium at a first height h and for a second medium at a second height H. The panels (23,24) have erect peripheral edges which are soldered to each other, the height thereof being different for the first and second type of panel. According to the invention, the first type of panel (23) has an edge (23a) corresponding to height h1 and a flank angle A. The second type of panel (24) has a higher edge which consists of at least three sections (24a, 24b, 24c), the height thereof being H1, H2 and H3. The first edge section (24a) corresponding to a height H1 and the third edge section (24c) corresponding to a height H3 respectively have a flank angle .alpha.. The second edge section (24b) corresponding to height H2 extends vertically in relation to the base of the panel (24e).