A method for manufacturing a microelectronic device comprising a membrane suspended over at least one final cavity, the method comprising: • providing a support substrate comprising a superficial layer having a first face, • forming at least one elementary cavity in the superficial layer of the support substrate, the at least one elementary cavity opening at said first face, and • providing a donor substrate having a first face, then • forming at least one membrane suspended over at least one final cavity, forming the membrane comprising: ∘ assembling the support substrate and the donor substrate by joining the first face of the support substrate to the first face of the donor substrate, so that the donor substrate covers at least partially the at least one elementary cavity, then ∘ thinning the donor substrate so as to form the membrane, characterised in that the method further comprises: • before or after forming the membrane, forming at least one anchoring pillar of the membrane, the at least one anchoring pillar being: ∘ based on at least one material different from a material forming the superficial layer, and ∘ configured to support at least one lower face of the membrane, at least at an edge of the membrane, and • after forming the at least one anchoring pillar, and after assembly, etching the superficial layer of the support substrate so as to enlarge the at least one elementary cavity, according to at least one direction parallel to a main plane of extension (x, y) of the first face of the superficial layer of the support substrate, to form the final cavity, said etching being configured so as to selectively etch the superficial layer with respect to the at least one material of the at least one anchoring pillar. • providing a support substrate comprising a superficial layer having a first face, • forming at least one elementary cavity in the superficial layer of the support substrate, the at least one elementary cavity opening at said first face, and • providing a donor substrate having a first face, then • forming at least one membrane suspended over at least one final cavity, forming the membrane comprising: ∘ assembling the support substrate and the donor substrate by joining the first face of the support substrate to the first face of the donor substrate, so that the donor substrate covers at least partially the at least one elementary cavity, then ∘ thinning the donor substrate so as to form the membrane, ∘ assembling the support substrate and the donor substrate by joining the first face of the support substrate to the first face of the donor substrate, so that the donor substrate covers at least partially the at least one elementary cavity, then ∘ thinning the donor substrate so as to form the membrane, • before or after forming the membrane, forming at least one anchoring pillar of the membrane, the at least one anchoring pillar being: ∘ based on at least one material different from a material forming the superficial layer, and ∘ configured to support at least one lower face of the membrane, at least at an edge of the membrane, and ∘ based on at least one material different from a material forming the superficial layer, and ∘ configured to support at least one lower face of the membrane, at least at an edge of the membrane, and • after forming the at least one anchoring pillar, and after assembly, etching the superficial layer of the support substrate so as to enlarge the at least one elementary cavity, according to at least one direction parallel to a main plane of extension (x, y) of the first face of the superficial layer of the support substrate, to form the final cavity, said etching being configured so as to selectively etch the superficial layer with respect to the at least one material of the at least one anchoring pillar.