A method of operating a semiconductor memory device includes an operation of applying a first voltage to selected bit lines, a second voltage to unselected bit lines and a common source line, and turning on drain and source selection transistors, an operation of applying a program voltage to a selected word line and a switch voltage to a switch word line, and applying a first pass voltage to first unselected word lines disposed between the switch word line and a common source line and between the selected word line and a bit line, and elevating the switch voltage to generate hot electrons and inject the hot electrons to a selected memory cell of the selected word line to program the selected cell.