A plate heat exchanger comprising a plurality of plates (2, 3, 4) arranged beside each other to form a plate package, each plate comprising a central area extending in parallel with an extension plane (p) of the plate (2, 3, 4) and comprising a corrugation of ridges and valleys, wherein the corrugation extends between an upper level (p') at a distance from the main extension plane (p) and a lower level (p") at a distance from and on an opposite side of the main extension plane (p) so that the ridges extend to the upper level (p') and the valleys to the lower level (p"), an edge area extending around the central area, and four porthole areas, each comprising an annular flat area, wherein the annular flat area is located at one of the upper level (p') and the lower level (p"), wherein the plates (2, 3, 4) comprise heat exchanger plates and at least a first end plate provided outside and adjoining an outermost one of the heat exchanger plates in the plate package, wherein each of the heat exchanger plates comprises four portholes extending through a respective one of the porthole areas, and wherein each of the porthole areas of the first end plate is closed by means of a plate portion surrounded by the annular flat area, each of the porthole areas of the first end plate comprises a number of protrusions arranged on and projecting from the annular flat area to one of the lower level (p") and the upper level (p'), characterized in that each porthole of the heat exchanger plates is defined by a porthole edge formed by the annular flat area, each of the protrusions of the first end plate, that project to the upper level (p'), abuts the annular flat area of the adjoining outermost heat exchanger plate, wherein the plates (2, 3, 4) also comprise a second end plate provided outside and adjoining the first end plate in the plate package, wherein each of the porthole areas of the second end plate is closed by means of a plate portion surrounded by the annular flat area, each of the porthole areas of the second end plate comprises a number of protrusions arranged on and projecting from the annular flat area to one of the lower level (p") and the upper level (p'), and each of the protrusions of the second end plate, that project to the upper level (p'), abuts a respective one of the protrusions of the annular flat area of the adjoining first end plate. a central area extending in parallel with an extension plane (p) of the plate (2, 3, 4) and comprising a corrugation of ridges and valleys, wherein the corrugation extends between an upper level (p') at a distance from the main extension plane (p) and a lower level (p") at a distance from and on an opposite side of the main extension plane (p) so that the ridges extend to the upper level (p') and the valleys to the lower level (p"), an edge area extending around the central area, and four porthole areas, each comprising an annular flat area, wherein the annular flat area is located at one of the upper level (p') and the lower level (p"), wherein the plates (2, 3, 4) comprise heat exchanger plates and at least a first end plate provided outside and adjoining an outermost one of the heat exchanger plates in the plate package, wherein each of the heat exchanger plates comprises four portholes extending through a respective one of the porthole areas, and wherein each of the porthole areas of the first end plate is closed by means of a plate portion surrounded by the annular flat area, each of the porthole areas of the first end plate comprises a number of protrusions arranged on and projecting from the annular flat area to one of the lower level (p") and the upper level (p'), characterized in that each porthole of the heat exchanger plates is defined by a porthole edge formed by the annular flat area, each of the protrusions of the first end plate, that project to the upper level (p'), abuts the annular flat area of the adjoining outermost heat exchanger plate, wherein the plates (2, 3, 4) also comprise a second end plate provided outside and adjoining the first end plate in the plate package, wherein each of the porthole areas of the second end plate is closed by means of a plate portion surrounded by the annular flat area, each of the porthole areas of the second end plate comprises a number of protrusions arranged on and projecting from the annular flat area to one of the lower level (p") and the upper level (p'), and each of the protrusions of the second end plate, that project to the upper level (p'), abuts a respective one of the protrusions of the annular flat area of the adjoining first end plate.