A nonvolatile memory device includes: a plurality of first reference cells that are connected in parallel, and are in an intermediate state between an erased state and a programmed state; a first current mirror circuit that generates a first mirror current proportional to a sum of currents flowing through the plurality of first reference cells in a state in which the plurality of first reference cells are selected; and a sense amplifier that, in a readout mode, generates a reference current based on at least the first mirror current, and reads out data stored in a memory cell by comparing a current flowing through the memory cell with the reference current.