We measured 1/fnoise in gate‐controlledp‐type implanted resistors in which the surface could be brought from accumulation to strong inversion. The noise increased by a factor of 150 when the surface was brought from accumulation to strong inversion. The results indicate strongly that the noise is due to the interaction of electrons in the inversion layer with the surface oxide. This gives rise to a fluctuating surface potential which in turn give a 1/fmodulation of the surface mobility.