A machine system comprises a machine body for processing a workpiece, cameras (61, 62) for capturing moving images of workpiece processing steps by the machine body, and a memory, and is provided withan information-processing device (80) for storing moving image data obtained by capturing moving images with the cameras (61, 62) to the memory. If a malfunction occurs in a processing step, the information-processing device (80) protects the moving image data for a previously set period comprising the time at which the malfunction occurred.