PURPOSE: To prevent description errors at real windows and to improve service by arranging the card prechecker for previously checking the error of marks described in OMR cards or the like separately from the windows, checking contents and urging correction concerning the card prechecker for checking cards.

CONSTITUTION: This device is provided with a card reader part 2 for reading a marked card (OMR card) 1, precheck function 4 for checking card data read by this card reader part 2 by collating them with previously registered contents, and correcting function 5 for urging the correction by displaying the wrong part and the error of the contents when the error is discriminated by this precheck function 4.