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 defining respective fluid channel of the first and second set of channels (401, 402) along a plurality of contact lines extending in parallel with a longitudinal fin direction, wherein, in a first channel of the first set of channels, a first fin structure comprises at least a first and a second part (210a1-2) arranged one after the other along the fin direction, wherein, in a first channel of the second set of channels, the first channel of the second set of channels being a neighbouring channel to the first channel of the first set of channels, a second fin structure comprises at least a first and a second part (210b1-2) arranged one after the other along the fin direction, wherein a central interface between the first and second parts (210a1-2) of the first fin structure extends across the longitudinal fin direction and is positioned at a first position along the fin direction, wherein a central interface between the first and second parts (210b1-2) of the second fin structure extends across the fin direction and is positioned at a second position along the fin direction, and The heat exchanger being characterized in that the first and second positions (P1, P2) are separated a longitudinal distance from each other. 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 defining respective fluid channel of the first and second set of channels (401, 402) along a plurality of contact lines extending in parallel with a longitudinal fin direction, wherein, in a first channel of the first set of channels, a first fin structure comprises at least a first and a second part (210a1-2) arranged one after the other along the fin direction, wherein, in a first channel of the second set of channels, the first channel of the second set of channels being a neighbouring channel to the first channel of the first set of channels, a second fin structure comprises at least a first and a second part (210b1-2) arranged one after the other along the fin direction, wherein a central interface between the first and second parts (210a1-2) of the first fin structure extends across the longitudinal fin direction and is positioned at a first position along the fin direction, wherein a central interface between the first and second parts (210b1-2) of the second fin structure extends across the fin direction and is positioned at a second position along the fin direction, and The heat exchanger being characterized in that the first and second positions (P1, P2) are separated a longitudinal distance from each other.