The present invention provides a flash memory device having a high degree of integration and high performance. The flash memory device has a double/triple gate structure where a channel is formed in a wall-shaped body. The flash memory device has no source/drain regions. In addition, although the flash memory device has the source/drain regions, the source/drain region are formed not to be overlapped with a control electrode. Accordingly, an inversion layer is induced by a fringing field generated from the control electrode, so that cell devices can be electrically connected to each other. The flash memory device includes a charge storage node for storing charges formed under the control electrode, so that miniaturization characteristics of cell device can be improved. According to the present invention, there is proposed a new device capable of improving the miniaturization characteristics of a MOS-based flash memory device and increasing memory capacity.