A semiconductor device includes a memory string coupled between a source line and a bit line and including a plurality of memory cells, a plurality of word lines, a peripheral circuit configured to apply a program voltage to a word line, apply a first pass voltage to a word line coupled to a first memory cell adjacent to the selected memory cell, and apply a second pass voltage to a second memory cell adjacent to the selected memory cell, and control logic configured to control the peripheral circuit so that the first pass voltage has a higher voltage level than the second pass voltage when a program target level of the selected memory cell is lower than a first threshold value, and the first pass voltage has a lower voltage level than the second pass voltage when the program target level is higher than a second threshold value.