A memory device includes a bit line, a reading word line, a bit line contact, an electrode, a writing word line and a contact tip. The bit line is formed on a substrate. The reading word line is formed over the bit line. The bit line contact is disposed between adjacent reading word lines. The electrode extends substantially in parallel to the reading word line and includes a conductive material being bent in response to an applied voltage. The writing word line is formed over the electrode and is separated from the electrode. The contact tip is formed at an end portion of the electrode and is separated from the reading and the writing word lines. The contact tip protrudes toward the reading word line or writing word line.