A method of an apparatus for diagnosing a memory including a storing module for storing diagnosis information relating to memory errors in a memory to be diagnosed, the apparatus capable of detecting memory errors, the method includes: testing the memory and detecting a memory error for each of a plurality of areas of the memory; dividing at least one of the areas into a plurality of sub-areas upon detection of a memory error in the at least one of the areas; testing the sub-areas and detecting a memory error for each of the plurality of the sub-areas; counting the number of sub-areas where a memory error is detected; and storing information of the number of the sub-areas where a memory error is detected together with information of the at least one of the areas containing the sub-areas into the storing module.