An electrode structure having at least two oxide layers that more reliably
switch and operate without the use of additional devices and a
non-volatile memory device having the same are provided. The electrode
structure may include a lower electrode, a first oxide layer formed on
the lower electrode, a second oxide layer formed on the first oxide layer
and an upper electrode formed on the second oxide layer wherein at least
one of the first and second oxide layers may be formed of a
resistance-varying material. The first oxide layer may be formed of an
oxide having a variable oxidation state.