PURPOSE: To permit continuous operation with no fear at all times by a balance where the data set in advance is temporarily stored when reading insert keys of the same article number successively, thereby to store the changed data.

CONSTITUTION: When it is required to temporarily change a unit price or data on tare of an article, the desired data is set with a ten-key switch 7 while leaving an insert key 16 inserted. Upon this, the changed data is indicated on a display 6. In this state, it may occur that a hand of the operator or the article touches the key 16 and then, the key 16 is once come off its reading position and set to the reading position again. There is provided a means for not cleaning the changed data and storing the same even in such state, so that the changed data is displayed. By so doing, even when the key 16 comes off the reading position and is reset thereto, the changed data is printed on a label and indicated on the display 6.