A data storage device includes a nonvolatile memory device including memory block groups and map data blocks, each memory block group including a first page group storing data transmitted from a host device and a second page group storing address mapping information corresponding to the data; and a controller configured to determine whether the number of valid data stored in a first memory block group in which the second page group is damaged is equal to or smaller than a size of an available capacity of an open map data block which is being used, and control, when the number of the valid data is equal to or smaller than the available capacity, the nonvolatile memory device to store address mapping information corresponding to the valid data of the first memory block group, in the open map data block.