Provided is a method of reading a flash memory device for depressing read disturb. According to the method, a first voltage is applied to a gate of the drain select transistor to turn on the drain select transistor, and a read voltage is applied to a gate of a selected transistor among the plurality of memory cells. Then, a pass voltage is applied to gates of unselected transistors among the plurality of memory cells. Furthermore, when the pass voltage is applied, a first pass voltage is applied and then a second pass voltage is applied after an elapse of a predetermined time following the applying of the first pass voltage. The second pass voltage has a level different from that of the first pass voltage.