PURPOSE: To provide the display method for through hole data on component graphics of printed wiring board CAD which enables data to be confirmed and corrected by layers of a printed wiring board which have plural conductive layers and component-mounted layers in the board.

CONSTITUTION: This display method displays the through hole data on the component graphics (like conductive pads) of necessary printed wiring board CAD; and sub-display screens (1:1, 1:2,...3:3, 3:4) finely fractionized and provided on the same display screen 11 are specified for layers relating to through holes provided at proper places of a multi-layered printed wiring board, and data by the layers which relate to the through holes provided at the proper places of the multi-layered printed wiring board among respective data (consisting of groups 12, 13, and 14) are displayed on the subordinate display screens in parallel.