In accordance with an embodiment, microelectromechanical microphone includes a holder and a sound detection unit carried on the holder. The sound detection unit includes a planar first membrane, a planar second membrane arranged at a distance from the first membrane, a low-pressure chamber formed between the first membrane and the second membrane, a reduced gas pressure relative to normal pressure being present in the low-pressure chamber, a reference electrode arranged at least in sections in the low-pressure chamber, where the first and second membranes are displaceable relative to the reference electrode by sound waves to be detected, the reference electrode includes a planar base section and a stiffening structure provided on the base section, and the stiffening structure is provided on a side of the base section that faces the first membrane or/and on a side of the base section that faces the second membrane.