A nonvolatile memory device includes: first memory cells connected to a first source line and a first bit line; second memory cells connected to a second source line and a second bit line; and a sense amplifier circuit connected to the first and second source lines and the first and second bit lines. The sense amplifier circuit includes: a first sense amplifier configured to apply a first read voltage to the first bit line and output a first amount of current of a selected first memory cell; a second sense amplifier configured to apply a second read voltage to the second bit line and output a second amount of current of a selected second memory cell; and a comparator configured to compare the first amount of current with the second amount of current to identify data of the selected first memory cell.