PURPOSE: To equalize substantially the number of renewing a content of respective addresses by successively adding and storing a data between a start mark and an end mark using cyclically an area.

CONSTITUTION: Throughout a head address #0Wa final address #n of a code area CE, a data code DC1 showing respective contents after a data DT1, a start mark SM showing a start point of a storing, and an end mark EM are successively stored like (A)W(F). Accordingly, in the code area CE, considering (A)W(D) as one cycle, the addresses #0W#n receive an equal number of storing operations, thereby an equalization of the number of the storing is realized. In order to repeat the similar cyle, every address, a content renewal of substantially equal times is executed, the number of the content renewal is not concentrated to a specific address but an entire life of the memory can be extended.