PURPOSE: To automatically extract the data on connection between a pad and a lead pin by providing a means which synthesizes the graphics and displays them on a screen and a means which secures a wiring between a pad graphic a lead graphic of the corresponding lead pin No based on the connection data on the screen where the synthetic graphic is displayed.

CONSTITUTION: A wire bonding drawing generating device 3 extracts the pad graphic data out of the chip layout data 4 produced by a layout design CAD tool 1 and also the lead graphic data on an inner lead part out of the lead frame data 5 on a package design CAD tool 2. Then a pad arrangement part is displayed on a graphic screen based on the extracted pad graphic data and performs the automatic wiring for connection of the bonding points for a lead graphic of the pin No corresponding to a pad graphic based on the connection data extracted on the screen. Thus a lead wiring diagram is obtained. Thus the connection data is automatically produced on the screen based on the pad graphic and the pin No.