A method for manufacturing an inductive conductivity sensor, wherein on both sides of a circuit board coils are placed surrounding an opening of the circuit board, and the circuit board with the coils is inserted into a housing. A sleeve is inserted through a first opening of the housing through the opening of the circuit board into the housing. The sleeve includes a first end section and a second end section and the sleeve is inserted with the first end section first into the housing, and wherein the sleeve is welded with the housing by means of a sonotrode by ultrasonic welding. Both the first end section as well as also the second end section of the sleeve are welded with the housing, wherein the sonotrode is applied exclusively on the sleeve on the side of the second end section. The invention relates further to an inductive conductivity sensor.
