There is provided an abnormal device determining means (CPU 51) which reads a tendency of displacement between the combination calculated weight Wc of the contents M and the post-discharge Ws measured value of the same contents M measured after such contents M have been bagged and which, based on the tendency of displacement so read, determines which one of the combination calculated value Wc and the post-discharge measured value Ws is abnormal, and a display device (54) for displaying a result of the determination. Thus, since based on the displacement tendency of the combination calculated value Wc and the post-discharge measured value Ws, which one of the combination calculated value Wc and the post-discharge measured value Ws is abnormal is determined, it can readily and easily grasped which one of the combination weighing apparatus (1) and the weight checker (300) suffers from a trouble.