The semiconductor memory device includes a variable resistance device having a solid electrolyte in a three-dimensional structure. The variable resistance device includes a first electrode; the solid electrolyte, which has at least two regions with different heights, formed on the first electrode; and a second electrode made of a conductive material formed on the solid electrolyte to cover the regions with different heights. In addition, a multibit semiconductor memory device is provided which includes a bias circuit that can control the intensity of a current and time the current is supplied to the variable resistance device inside a memory cell in multiple steps to configure multibits.