In a nonvolatile semiconductor memory device, a memory cell array has a plurality of nonvolatile memory cells arranged in a matrix. A selecting section selects as selection memory cells, at least two of the plurality of nonvolatile memory cells from the memory cell array. A write section applies to the selection memory cells, a gate voltage which increases step by step, until a threshold voltage of each of the selection memory cells reaches a target threshold voltage, such that the threshold voltage increases step-by-step.