A POS registering system is disclosed, that comprises a menu having a plurality of menu keys and at least one selection key, at least one sales item being assigned to each of the menu keys, each of the selection key being used to select one of sales items assigned to each of the menu keys, a table containing entries of sales item data of the sales items assigned to each of the menu keys, the sales item data including a sales item name and a prices of each sales item, and a display device, wherein when an operation including a selecting a menu key is performed for designating a sales item on the menu, entries of sales item data of all sales items assigned to the selected menu key are searched from the table and all the searched entries of sales item data are displayed on the display device in such a manner that they are distinguished from entries of correction alternative sales item data of the remaining sales items assigned to the menu key, and wherein when an operator selects one of the entries of the correction alternative sales item data displayed on the display device, the selected entry of the correction alternative sales item data is treated as an entry to be processed.