A semiconductor integrated circuit device is provided on a semiconductor substrate, and includes a plurality of word lines, a plurality of data lines, and a plurality of electrically programmable and erasable non-volatile memory cells respectively coupled to the plurality of word lines and to the plurality of data lines. The erasable non-volatile memory cell each includes a MIS transistor having a floating gate having a first level polycrystalline silicon layer, a source, and a drain coupled to the corresponding data line, and a control gate formed of a semiconductor region in the semiconductor substrate, the control gate being coupled to the corresponding word line.