Abstract: A flowmeter for gases and liquids utilized a semi-conductor body disposed in the gas or liquid, respectively, one end of the semi-conductor body being heated by means of an electric resistance wire such that at temperature difference, and thereby a voltage difference is realized between the ends of the semi-conductor body. The reduction of the temperature difference, and thereby of the voltage difference, varying with the flow rate is utilized for determining the flow rate. This is effected with the assistance of an amplifier across whose input the semi-conductor body is coupled-in and on whose output a signal representing the flow rate appears.