A non-volatile semiconductor memory device comprises a memory cell array of data-rewritable non-volatile memory cells or memory cell units containing the memory cells, and a plurality of word lines each commonly connected to the memory cells on the same row in the memory cell array. In write pulse applying during data writing, a high voltage for writing is applied to a selected word line, and an intermediate voltage for writing is applied to at least two of non-selected word lines. The beginning of charging a first word line located between the selected word line and a source line to a first intermediate voltage for writing is followed by the beginning of charging a second word line located between the selected word line and a bit line contact to a second intermediate voltage for writing.