The present technology relates to an electronic device. A memory device configured to perform a sensing operation based on a charge degree of a sensing node includes a memory cell array including a plurality of memory cells, a peripheral circuit including a page buffer connected to a selected memory cell among the plurality of memory cells through a bit line, and configured to perform a sensing operation on the selected memory cell, and control logic configured to control the peripheral circuit to precharge a source line among lines connected to the memory cell array and perform the sensing operation based on a degree at which a sensing node in the page buffer is charged, during the sensing operation.