Provided are a nonvolatile memory and a data reading method of reading data from a nonvolatile memory by the memory controller. The data reading method includes reading data from memory cells of the nonvolatile memory, storing the read data in the internal memory, overwriting some of the read data stored in the internal memory with backup data, performing an error correction operation using the backup data stored in the internal memory, and overwriting the backup data stored in the internal memory with data corrected by the error correction operation.