A method for manufacturing a micro-electro-mechanical system, MEMS, including a first MEMS device and a second MEMS device, comprising the steps of: forming, on a substrate, a first electrode of the first MEMS device; forming, on the first electrode, a first sacrificial layer (8, 8') of a material that may be removed through an etching chemical solution; forming, on the first sacrificial layer (8, 8'), a protection layer impermeable to said etching chemical solution; selectively removing portions of the protection layer to expose a respective sacrificial portion of the first sacrificial layer (8, 8'); forming, on the sacrificial portion, a membrane layer of a porous material, which is permeable to said etching chemical solution; forming a cavity by removing the sacrificial portion through the membrane layer using said etching chemical solution; forming a first structural layer which seals pores of the membrane layer and forms, with the membrane layer, a suspended structure (17, 20) of the first MEMS device, said suspended structure (17, 20) being a second electrode capacitively coupled to the first electrode through the cavity; - forming, above the first structural layer, a second sacrificial layer of a material which may be etched through said etching chemical solution; - forming a second structural layer above, and in contact with, the second sacrificial layer; - patterning the second structural layer to concurrently form movable structures of the second MEMS device and biasing structures of the first and second electrodes of the first MEMS device (51, 52); - removing selective portions of the second sacrificial layer through said etching chemical solution, making said movable structures of the second MEMS device and said suspended structure of the first MEMS device free to move according to respective degrees of freedom. forming, on a substrate, a first electrode of the first MEMS device; forming, on the first electrode, a first sacrificial layer (8, 8') of a material that may be removed through an etching chemical solution; forming, on the first sacrificial layer (8, 8'), a protection layer impermeable to said etching chemical solution; selectively removing portions of the protection layer to expose a respective sacrificial portion of the first sacrificial layer (8, 8'); forming, on the sacrificial portion, a membrane layer of a porous material, which is permeable to said etching chemical solution; forming a cavity by removing the sacrificial portion through the membrane layer using said etching chemical solution; forming a first structural layer which seals pores of the membrane layer and forms, with the membrane layer, a suspended structure (17, 20) of the first MEMS device, said suspended structure (17, 20) being a second electrode capacitively coupled to the first electrode through the cavity; - forming, above the first structural layer, a second sacrificial layer of a material which may be etched through said etching chemical solution; - forming a second structural layer above, and in contact with, the second sacrificial layer; - patterning the second structural layer to concurrently form movable structures of the second MEMS device and biasing structures of the first and second electrodes of the first MEMS device (51, 52); - removing selective portions of the second sacrificial layer through said etching chemical solution, making said movable structures of the second MEMS device and said suspended structure of the first MEMS device free to move according to respective degrees of freedom. - forming, above the first structural layer, a second sacrificial layer of a material which may be etched through said etching chemical solution; - forming a second structural layer above, and in contact with, the second sacrificial layer; - patterning the second structural layer to concurrently form movable structures of the second MEMS device and biasing structures of the first and second electrodes of the first MEMS device (51, 52); - removing selective portions of the second sacrificial layer through said etching chemical solution, making said movable structures of the second MEMS device and said suspended structure of the first MEMS device free to move according to respective degrees of freedom.