PURPOSE: To eliminate the overlooking of the collating errors of the input data and at the same time to omit the expensive labor.

CONSTITUTION: The initial input of data is carried out by an OCR device 3, and the read image data are converted into the character data and registered in a data file 5. Then a data collator means 6 reads the data out of the file 5 and input the collation data through a collation data input device 8. The means 6 compares logically both data with each other. If no coincidence is secured between both data, the correction input is carried out through the device 8 so that the correct data are obtained.