An openable Plate&Shell –type plate heat exchanger (1), which comprises a plate pack (2) arranged inside the outer casing and an additional end plate (4) attached to the support plate (3) of the plate pack and the openable cover plate (7) of the outer casing. The inlet and outlet (10, 11) connections for the first heat exchange medium are attached only to the first cover plate (7) of the outer casing and/or the openings of the additional end plate (4), the connecting points between the additional end plate (4) and the openings (14, 14') of the support plate (3) of the plate pack are free of the welded joints. The invention relates also the method for replacing the plate pack of the plate heat exchanger.
