PROBLEM TO BE SOLVED: To easily confirm an influence of extraction or reintroduction of a board in a solder printing process on the board quality. SOLUTION: In the solder printing inspection machine, identification codes and inspection time of hourly inspection target boards are accumulated in a memory. The accumulated data are searched for a board whose identification code agrees with that of the current inspection target board, while the accumulated data are traced back one by one. When the corresponding board is found, it is recognized that the board was extracted because of its defect and the inspection target board is the reintroduced board previously extracted. A graph which shows information expressing the quality of each board arrayed in time series is produced based on each inspection result and is displayed on a monitor. In the data included in the graph, the data corresponding to the board recognized as the reintroduced board are explicitly shown by a letter "R". COPYRIGHT: (C)2011,JPO&INPIT