The movable element is produced from a structural layer (7) by masking, with filled contact holes (10) between a lower metallisation plane (14,16) and insulation regions (6). It is formed on the surface of a substrate and has a covering layer (15) facing the surface across a cavity and contg. etched holes. A closure layer (21) of e.g. dielectric material is applied overall and may contain metallised contact holes. A further metallisation plane (22) may be added on the dielectric. The covering layer is supported on pillars (12) or bars (11).
