Abstract A new heated microgas-sensor with only 80 μm ×80 μm active heater area and excellent long-term stability is presented. Using a previously presented SiC based microhotplate and depositing an In 2 O 3 thin film layer on top of the interdigital electrode (IDE) structure an NO 2 sensor for the MAK-range (German maximum workplace concentration limit: 5 ppm) was fabricated. The microhotplate allows a maximum operating temperature of up to 650°C, which is limited only by the IDE metallisation stability. When using In 2 O 3 layers for NO 2 detection, the hotplates’ low operating power of 20 mW allows the continuous operation at operating temperature with an AAA battery cell for 75 h. More than 20,000 work cycles of 1 min could be realised before device failure leading to a life time of over half a year when sampling the ambient gas every 10 min.