A non-volatile memory device including a first floating-gate element, a second floating-gate element, and a selection gate element. The first floating-gate element includes a gate electrode configured to generate a read current based on the read voltage, the control voltage, and the electrical state of the gate electrode. The second floating-gate element shares a gate electrode with the first floating-gate element and is configured to determine the electrical state of the gate electrode based on the write voltage and the control voltage. The selection gate element is electrically coupled to the first floating-gate element and the second floating-gate element and is configured to generate the control voltage according to the word driving voltage and the source driving voltage.