Abstract: An electronic cash register including a printing member comprising a means for presetting a validation printing operation request when said cash register is needed to produce a desired validation print of a predetermined processed data, a means for generating an enable signal by which said cash register is compelled to perform the validation print, the enable signal being generated when the validation printing operation request has been preset with said presetting means and a predetermined cash register function corresponding to the predetermined processed data has been completed in said cash register, receiving means for receiving a validation paper, a detecting means coupled to the receiving means for detecting if said validation paper is present in the receiving means, and an instructing means for instructing said printing member to print said predetermined processed data on the validation paper, wherein when said validation printing request has been preset, said printing member performs printing said pred