Abstract: A microvacuum sensor has an expanded sensitivity range, wherein a thin membrane having poor thermal conductivity is freely suspended on a semiconductor single-crystal. A thin metallic heating layer, preferably of aluminum, is arranged on the membrane. The membrane surface is suspended by at least one web of the membrane material. The heating layer has an extremely low emissivity of less than 0.1 in the near infrared range. A film resistor having the same temperature coefficient as the metallic heating layer is arranged on the sensor chip in the region of the solid silicon for temperature compensation of temperature fluctuations. Members having a planar mirrored wall are arranged parallel to the surfaces of the membrane at a spacing of less than 5 .mu.m from the membrane. These members act as a heat sink relative to the membrane. Gas from the environment of the sensor can freely circulate between the membrane and the wall surfaces.