the faulty block located within the normal data regions is replaced with the block which is not the faulty block which is located within the replacement regions so as to correspond thereto further giving the description with respect to the practical example in the case where by employing 32 mbits flash memory manufactured by hitachi ltd which is previously taken as an example 20 chips semiconductor memory device is constructed the number of blocks is 163 840 since the address value thereof is 18 bits the fault address registration requires 18 bits every registration on the other hand assuming that the upper limit of the number of faulty regions is 5 of the overall regions 8 192 faulty blocks will be present at maximum this can be represented with 14 bits as a result one fault registration requires the data of 32 bits in total of the faulty address values and the replacement address values and hence the memory with 256 kbits capacity is required for 8 192 blocks currently however the memory with capacity of this degree is very cheep in this example the total storage capacity of the normal data regions is 163 840 8 192 155 648 blocks but in the case where the fault registration memory is the nonvolatile memory in order to store the faulty registered data in the nonvolatile memory the additional 64 blocks are further used fig3 is a diagram useful in explaining a method of using the administrative information regions within the nonvolatile memory 1 in the figure reference numeral 21 designates the data storage contents of.