Classical modeling of fully inverted SOI MOSFET (FI MOSFET) has been performed. In FI MOSFETs, the top Si layer is thinner than the thickness of the inversion layer at the conducting state and so the depleted region in the top Si layer is completely eliminated. It was found that the gate electric field induces carriers in the channel more effectively in FT MOSFET than in the fully depleted SOI MOSFETs (FD MOSFET), so that the short channel effects can be suppressed significantly.