A nonvolatile semiconductor memory device comprises a readout circuit which reads data stored in a selected memory cell by applying predetermined voltage to the selected memory cell and a reference cell such that currents corresponding to the respective threshold voltage may flow, and comparing the current flowing in the selected memory cell with the current flowing in the reference cell. The readout circuit commonly uses the reference cell set in the same storage state for normal readout and for readout for program verification, and when the predetermined voltage is applied to the selected memory cell and the reference memory cell at the time of the readout for the program verification, it sets an applying condition to the reference memory cell such that its storage state may be shifted more in the program state direction than that in an applying condition at the time of the normal readout.