The current-voltage characteristics of a new a-Si:H static induction transistor(SIT) are calculated by taking into account the gap state density. It is shown that SIT, in which the finger-plate Schottky gate electrode with a spacing of about 3∼5 μm is buried in the i layer of a-Si:H n +in + structure, can achieve a high on/off current ratio of about 10 8 in the gate voltage range less than ten volts for the gap state density near the Fermi level being 5×10 15 ∼ 1×10 16 cm −3eV −1. The operation frequency of SIT is expected to exceed a few MHz because the transconductance is about 400 times larger than that of a conventional a-Si:H thin-film transistor(TFT).