Patent ID: 8830757

Claim:
A method for operating a nonvolatile semiconductor memory device, the nonvolatile semiconductor memory device including a memory unit having a memory string and a control unit controlling the memory unit, the memory string including a plurality of transistors connected in series and has a first group being part of the plurality of transistors, a first adjusting transistor connected next to the first group, and a second group including transistors connected to the side opposite the first group with respect to the first adjusting transistor, threshold values being set to the plurality of transistors, respectively, according to charges stored in a charge storage film, the method comprising: rewriting the threshold values of the transistors of only the first group, and then performing control so as to set a first threshold value for adjustment to the first adjusting transistor to adjust an amount corresponding to relative variations in the threshold values of the transistors of the second group, the relative variations being caused by the rewrite of the threshold values of the transistors of the first group.