The invention relates to a heat transfer plate (1) intended to constitute, together with other heat transfer plates, a plate stack (2) with permanently connected plates for a heat exchanger (3), which heat transfer plate (1) has a first long side (4) and an opposite second long side (5), a first short side (6) and an opposite second short side (7), a heat transfer surface (8) exhibiting a pattern (9) of ridges (10) and valleys (11), first and second port regions (12 and 13), the first port region (12) being situated in a first corner portion (14) formed at the meeting between the first long side (4) and the first short side (6), the second port region (13) being situated in a second corner portion (15) formed at the meeting between the second long side (5) and the first short side (6), and the first port region (12) being connected to a number of ridges (10a-d) and valleys (11a-e), which ridges (10a-d) and valleys (11a-e) have in principle an extent from the first port region (12) diagonally towards the second long side (5).