CIRCUIT DIAGRAM INPUT SYSTEM

PURPOSE:To easily trace an inter-sheet connected signal line. CONSTITUTION:A connection extracting part 5 extracts the discrimination information of the inter-sheet connected signal line on a circuit diagram from circuit diagram information stored in a data storage device 3. When a prescribed symbol to show inter-sheet connection on the circuit diagram on a display device is instructed by operation at an input/output device, a connection retrieving part 6 retrieves other sheets containing the discriminating information of the signal line connected to the symbol from the circuit diagram information stored in the data storage device 3 on the basis of the discrimination information of the signal line which is extracted by the connection extracting part 5. A circuit diagram display part 7 displays this sheet retrieved by the connection retrieving part 6 on the display device, and displays the signal line of a connection destination by enhancing it.