Abstract: The invention relates to a plate-type heat exchanger comprising a stack (1) of plates (2) for heat exchange between fluids which circulate between each other, said stack being placed within a pressure vessel (3). The invention is characterized in that it comprises rigid means for suspension of said stack (1) from said vessel (3) at the level of at least a first collector circuit which comprises a first connecting box (21; 23) at the upper end of the stack (1) and guides a first of said fluids between said end and the exterior of the vessel (3).