Method for manufacturing an electroacoustic transducer comprising: - a frame; - an element moveable with respect to the frame, the moveable element comprising a membrane and a structure for rigidifying the membrane; - a first transmission arm , the moveable element being coupled to an end of the first transmission arm ; method comprising the following steps: - providing (S1) a stack successively comprising a substrate , a first sacrificial layer and a first structural layer ; - forming (S2) a second sacrificial layer on the first structural layer , the second sacrificial layer comprising disjointed first and second portions ; - forming (S3) a second structural layer on the first structural layer and the second sacrificial layer ; - etching (S4) the second structural layer so as to expose the first portion of the second sacrificial layer and to delimit the rigidification structure of the moveable element , the second portion of the second sacrificial layer being encapsulated by the rigidification structure ; - etching (S4) the first structural layer to the first sacrificial layer so as to delimit the membrane of the moveable element ; - etching (S5) the first portion of the second sacrificial layer so as to expose a first face of the membrane and to etch a portion of the first sacrificial layer , thereby forming a cavity which extends under the rigidification structure ; - etching (S7) the substrate so as to delimit the first transmission arm and to release at least partially the moveable element while opening into the cavity , the first sacrificial layer and the second portion of the second sacrificial layer serving as stop layer to the etching; - etching (S8) the first sacrificial layer so as to expose a second opposite face of the membrane . - a frame; - an element moveable with respect to the frame, the moveable element comprising a membrane and a structure for rigidifying the membrane; - a first transmission arm , the moveable element being coupled to an end of the first transmission arm ; - providing (S1) a stack successively comprising a substrate , a first sacrificial layer and a first structural layer ; - forming (S2) a second sacrificial layer on the first structural layer , the second sacrificial layer comprising disjointed first and second portions ; - forming (S3) a second structural layer on the first structural layer and the second sacrificial layer ; - etching (S4) the second structural layer so as to expose the first portion of the second sacrificial layer and to delimit the rigidification structure of the moveable element , the second portion of the second sacrificial layer being encapsulated by the rigidification structure ; - etching (S4) the first structural layer to the first sacrificial layer so as to delimit the membrane of the moveable element ; - etching (S5) the first portion of the second sacrificial layer so as to expose a first face of the membrane and to etch a portion of the first sacrificial layer , thereby forming a cavity which extends under the rigidification structure ; - etching (S7) the substrate so as to delimit the first transmission arm and to release at least partially the moveable element while opening into the cavity , the first sacrificial layer and the second portion of the second sacrificial layer serving as stop layer to the etching; - etching (S8) the first sacrificial layer so as to expose a second opposite face of the membrane . <EOS>