The invention relates to an air mass meter with a sensor element, wherein an air mass flow to be measured moves across the sensor element and wherein the sensor element is formed as a micro-electro-mechanical system having a membrane, on which a heating element is formed. An electrical measuring resistor and at least two electrical comparison resistors are arranged upstream and downstream of the heating element in the direction of the air mass flow, and a first temperature sensor element and a second temperature sensor are formed by the electrical connection of a respective measuring resistor to at least two comparison resistors. In order to eliminate distortion of the measuring results due to contamination of the sensor element, or at least to keep the distortion within narrow limits, the first temperature sensor element is formed as a series circuit of resistors on the sensor element, with a measuring resistor arranged upstream of the heating element relative to the air mass flow and two comparison resistors arranged downstream of the heating element relative to the air mass flow, and the second temperature sensor element is formed as a series circuit of resistors on the sensor element, with a measuring resistor arranged downstream of the heating element relative to the air mass flow and two comparison resistors arranged upstream of the heating element relative to the air mass flow.