A heat exchanger comprising a stack of heat exchanger plates stacked one on top of the other along a stacking direction, a first set of channels formed in every first second interspace between the heat exchanger plates, a second set of channels formed in every second second interspace between the heat exchanger plates, wherein, in each of the channels in the first and second set of channels (401, 402) fin structures formed of sheets being folded back and forth are positioned between the heat exchanger plates such that the respective fin structure abuts the heat exchanger plates along a plurality of contact lines having a main extension extending in parallel with a longitudinally extending fin direction thereby defining plurality of fluid channels forming said first and second set of channels (401, 402), wherein each heat exchanger plate comprises four through-going openings (201, 202, 211, 212) formed at a respective corner portion of the respective heat exchanger plate and configured to form a first inlet port extending through the stack along the stacking direction, a first outlet port extending through the stack along the stacking direction, a second inlet port extending through the stack along the stacking direction, and a second outlet port extending through the stack along the stacking direction, the first inlet port and first outlet port being in fluid connection with each other via the first set of channels and the second inlet port and second outlet port being in fluid connection with each other via the second set of channels, wherein the heat exchanger further comprises, in each interspace between the heat exchanger plates, a distribution structure at the respective inlet port (201, 202) and a collection structure at the respective outlet port (211, 212), wherein the respective distribution structure, respectively the respective collection structure is positioned between the respective port (201, 202, 211, 212) and the respective fin structure in the respective first and second set of channels (401, 402), characterized in that an internal interface between the respective distribution structure and the fin structure and/or an internal interface between the respective collection structure and the fin structure in the respective channel of the first set of channels and/or in the respective channel of the second set of channels is inclined relative to the longitudinally extending fin direction and is inclined also relative to a transversal direction. a first set of channels formed in every first second interspace between the heat exchanger plates, a second set of channels formed in every second second interspace between the heat exchanger plates, wherein, in each of the channels in the first and second set of channels (401, 402) fin structures formed of sheets being folded back and forth are positioned between the heat exchanger plates such that the respective fin structure abuts the heat exchanger plates along a plurality of contact lines having a main extension extending in parallel with a longitudinally extending fin direction thereby defining plurality of fluid channels forming said first and second set of channels (401, 402), wherein each heat exchanger plate comprises four through-going openings (201, 202, 211, 212) formed at a respective corner portion of the respective heat exchanger plate and configured to form a first inlet port extending through the stack along the stacking direction, a first outlet port extending through the stack along the stacking direction, a second inlet port extending through the stack along the stacking direction, and a second outlet port extending through the stack along the stacking direction, the first inlet port and first outlet port being in fluid connection with each other via the first set of channels and the second inlet port and second outlet port being in fluid connection with each other via the second set of channels, wherein the heat exchanger further comprises, in each interspace between the heat exchanger plates, a distribution structure at the respective inlet port (201, 202) and a collection structure at the respective outlet port (211, 212), wherein the respective distribution structure, respectively the respective collection structure is positioned between the respective port (201, 202, 211, 212) and the respective fin structure in the respective first and second set of channels (401, 402), characterized in that an internal interface between the respective distribution structure and the fin structure and/or an internal interface between the respective collection structure and the fin structure in the respective channel of the first set of channels and/or in the respective channel of the second set of channels is inclined relative to the longitudinally extending fin direction and is inclined also relative to a transversal direction.