A method for manufacturing a suspended membrane in a single-crystal semiconductor substrate, including the steps of: forming in the substrate an insulating ring delimiting an active area, removing material from the active area, successively forming in the active area a first and a second layers, the second layer being a single-crystal semiconductor layer, etching a portion of the internal periphery of said ring down to a depth greater than the thickness of the second layer, removing the first layer so that the second layer formed a suspended membrane anchored in the insulating ring.