A method of manufacturing a heat and humidity exchange plate (10) of an air-to-air counterflow enthalpy heat exchanger, which comprises a supporting member (101) and at least one polymeric vapour-permeable membrane (102), characterized in that it comprises the following successive steps:
- a - continuous formation of a semi-finished product for the supporting member (101) in the form of an expanded metal structure (1010) from a strip of thin metal foil (1011), whereby the operations of slitting in the transverse direction, stretching in the longitudinal direction and rolling over the entire width of the strip are successively performed;
- b - providing the expanded metal structure (1010) according to the preceding step with a thin vapour-permeable polymeric membrane (102);
- c - on the expanded metal structure (1010) provided with the vapour-permeable polymeric membrane (102), formation of corrugated and embossed shape elements of the future heat and humidity exchange plate (10) of a counterflow enthalpy heat exchanger (1) by means of omnidirectional deformation;
- d - creating a circumferential shape of the heat and humidity exchange plate of the counterflow enthalpy heat exchanger (1) by removing excess edges.