The first high resolution rotational spectrum of H2SiO in the gas phase has been obtained. This molecule was identified among several short-lived unknown species produced by a low power "abnormal" glow discharge in a mixture of SiH4, O-2, and Ar. On/off modulation of the discharge allowed lines belonging to each species to be characterized by their lifetime measured using a digitizing oscilloscope. In total 107 lines of H2SiO were measured between 140 and 470 GHz. Evidence for a possible large amplitude motion has been found from anomalies in the fit of close lying K-a doublers.