PURPOSE: To reproduce operation history information and the pictures of the external condition of an operator while linking them with each other and to easily confirm and improve the problem of stacks.

CONSTITUTION: When an operation for operating the stack is performed or when a card is displayed on a display device 1, the frame number of the pictures of the external condition of the operator recorded by a VTR 5 is received from a VTR control part 6 and is recorded in an operation history information management part 13 as the operation history information, an operation history reproduction part 9 reads the recorded operation history information and the VTR control part 6 retrieves the pictures based on the frame number in the operation history information. Or, the operation history reproduction part 9 receives the frame number from the pictures reproduced by the VTR 5 and retrieves the operation history information based on the frame number. Thus, the pictures and the operation history information are linked with each other and reproduced.