A charge trap insulator memory device comprises a plurality of memory cells connected serially, a first switching device, and a second switching device. In the plurality of memory cells, data applied through a bit line depending on potentials applied to a top word line and a bottom word line are stored in a charge trap insulator or the data stored in the charge trap insulator are outputted to the bit line. The first switching element selectively connects the plurality of memory cells to the bit line in response to a first selecting signal. The second switching element selectively connects the plurality of memory cells to a sensing line in response to a second selecting signal.