A memory device includes a memory cell array including a plurality of memory cells, and a page buffer circuit including a plurality of page buffer units respectively connected to the plurality of memory cells via a plurality of bit lines, and a plurality of cache latches respectively corresponding to the plurality of page buffer units. Each of the plurality of page buffer units includes a pass transistor that is connected to a corresponding sensing node and is driven according to a pass control signal, and the memory device is configured such that in a data sensing period, a sensing node of a selected page buffer unit among the plurality of page buffer units is actively connected to a sensing node of an unselected page buffer unit among the plurality of page buffer units.