Memory device while erase may be performed simultaneous front groups in addition necessary even after erase simultaneous stores data thereby part of real estate can be conserved as the device memory by to unauthorized of reset, and the selection control signal to the tuner thereby enabling high degree of preservation of the part of the data to enable treating an underwater bed is intended. A nonvolatile memory device group (1); nonvolatile memory element army data indicating the regions non-erased a responsible pharmacist, a storing means; nonvolatile memory in element army external block and in response to data force when a heel, data is designated by and are designated to be non-erased area erase operations of a and, nonvolatile memory element army erase region so as to effect the first operation can be executing erase control means (36) is formed of. When erase simultaneous front data memory in part to counterfeiting and also the. capable of reducing a test time.