A storage device includes a memory device configured to perform a read operation on a selected word line among a plurality of word lines, and a memory controller configured to control the memory device to: perform the read operation, perform a read retry operation on the selected word line, by changing a read voltage level, when the read operation fails, and perform an additional read retry operation on the selected word line, by changing the read voltage level and an application time of voltages related to the read operation, depending on whether the selected word line is a set word line, when the read retry operation fails.