In a method of manufacturing a capacitive electromechanical transducer, a first electrode (8) is formed on a substrate (4), an insulating layer (9) which has an opening (6) leading to the first electrode is formed on the first electrode (8), and a sacrificial layer is formed on the insulating layer. A membrane (3) having a second electrode (1) is formed on the sacrificial layer, and an aperture is provided as an etchant inlet in the membrane. The sacrificial layer is etched to form a cavity (10), and then the aperture serving as an etchant inlet is sealed. The etching is executed by electrolytic etching in which a current is caused to flow between the first electrode (8) and an externally placed counter electrode through the opening (6) and the aperture of the membrane.