A plate evaporator apparatus of the falling film type comprises a housing having an inlet for liquid to be evaporated and having mounted therein a package of heat transferring plates with plate interspaces, every second one of which forms an evaporation space for at least partial evaporation of liquid and the other plate interspaces forming condensation spaces for at least partial condensation of a heat emitting vapor. First seals delimit distribution chambers, each of which is in liquid flow communication with at least one evaporation space by flow ways spaced apart along the package width. The heat transferring plates have through openings aligned to form a passage extending through the plate package. A pipe is connected to the inlet and has apertures distributed along its length in flow communication with the distribution chambers, for supplying the liquid to be evaporated from the inlet to the distribution chambers through the apertures.