PURPOSE: To easily detect the program state of a nonvolatile memory by reading out the storing information of the memory cell to the outside by selecting the data read out of a cell group in accordance with the storing information of the nonvolatile memory cell.

CONSTITUTION: Since reading out data are selected based on the data stored in a nonvolatile memory cell 23, the storing data of the memory cell 23 can be read out equivalently by the selection when cell groups 11 and 12 storing the data corresponding to the storing data of the memory cell 23 are read out at the time of reading out the storing data of the memory cell 23. The transmition route of the read out data is a usual route and no special reading out route, terminal pin, etc., are required for transmitting the storing data of the memory cell 23. Therefore, the state of the program of the nonvolatile memory cell 23 can be detected easily.