A multiple-bit cell transistor includes a P type silicon substrate, a gate insulation layer, a pair of N type source/drain regions, a pair of tunnel insulation layers, and a pair of floating gates. The silicon substrate is formed with a projection while the floating gates each are positioned on one of opposite side walls of the projection. Inter-polycrystalline insulation layers each are formed on one of the floating gates. A control gate faces the top of the projection via the gate insulation layer. An N type region is formed on each side of the projection and contacts the source/drain region adjoining it. The cell transistor lowers a required write voltage, broadens a current window, and enhances resistance to inter-band tunneling.