PURPOSE: To remove a useless memory area and to rapidly specify data to be processed by forming a table for holding idle area pointers of a memory and specifying the data of character string to be processed in the memory while referring the table.

CONSTITUTION: Respective records are inputted in accordance with the recording format of a data file to be processed, the storing addresses and sizes of respective items in the memory are set up in the table, and at the time of completing the input of the records, idle area pointers in the memory are set up in the table. The data to be processed are specified while referring the table and the registering, deleting and correcting processing of the data is executed while updating the table. Since a memory area corresponding to the size of respective items of the record can be secured, a useless area is not generated. In addition, since only the necessary data are retrieved by referring the address table without directly retrieving the character string data, the processing speed can be increased.