An adaptive control was proposed early by Na and No (1990) for the control of the water level of steam generators. In this work the algorithm of the controller is changed a little. In order to know if this controller is robust in modeling errors and in high frequency measurement noises in controlling the water level of steam generators, a scaled-down steam generator is made which has the dimension of nearly one-tenth of the reference height and pressure, and 1/10,000 of its power. The controller is studied experimentally by implementing it to the mock-up of a nuclear steam generator. It is known that the controller is robust in unmodelled dynamics.