A nonvolatile memory device includes a memory cell array in a first semiconductor layer and including a first memory cell connected to a first word line and a first bit line and a second memory cell connected to the first word line and a second bit line; a page buffer circuit in a second semiconductor layer and including a first page buffer connected to the first bit line, and a second page buffer connected to the second bit line; and a page buffer controller in the second semiconductor layer. The page buffer controller controls the first and second page buffers so that a develop timing of a first sensing node of the first page buffer is different from a develop timing of a second sensing node of the second page buffer. The first page buffer is closer to a through electrode region than the second page buffer.