  We investigate a lateral semiconductor quantum dot with a large number of
electrons in the semi-open Fano regime. In transport measurements we observe
three stable series of Fano resonances with similar lineshapes. We present a
simple model explaining the temperature and V_{SD} dependence of the
resonances. The Fano regime allows to investigate phase and coherence of the
electronic wave function and astonishingly, we find no signs of decoherence in
our system.
