A detector for detecting electromagnetic radiation includes a substrate and at least one microstructure including a radiation-sensitive membrane extending substantially opposite and away from the substrate. The membrane is mechanically attached to at least two longilinear, collinear retention elements, at least one of which is mechanically connected to the substrate by an intermediate post. The membrane is in electrical continuity with the substrate. At least two collinear legs are attached to each other at the level of their ends which are attached to the membrane by a mechanical connector which is substantially co-planar with the legs and membrane. The other end of at least one of the legs is integral with a rigid cross piece which is substantially co-planar with the legs and extends substantially at right angles relative to the main dimension of the legs. The cross piece is integral with the post which is integral with the substrate.