Variation in threshold voltages in a device operation is reduced.An insulator layer which is disposed to be opposed to a channel region 41 of a MOS transistor and is formed to have a laminated structure of a silicon nitride film 83 and a silicon oxide film 83 and an inverted signal input unit which inputs a signal obtained by inverting an input signal inputted into a source region 43 of a MOS transistor into a channel region 41 are provided and the inverted signal input unit includes another gate electrode 82 which is formed on an extended portion of the channel region 41 of the gate electrode 81 in a manner to be adjacent to the gate electrode 81 of the MOS transistor and a CMOS circuit 80 which inverts an input signal inputted into the source region 43 of the MOS transistor in accordance with an input value of the input signal and inputs a signal obtained through inversion in the CMOS circuit 80 into another gate electrode 82.