A flowmeter including a system chip with a silicon substrate provided on a carrier, in an opening whereof at least one silicon flow tube is provided for transporting a medium whose flow rate is to be measured, the tube having two ends that issue via a wall of the opening into channels coated with silicon nitride in the silicon substrate, wherein the flow tube forms part of a Coriolis flow sensor and/or a thermal flow sensor, and wherein the channels are preferably in communication through the carrier with connection lines to the external world.