A multilayer wiring board formed by laminating a plurality of dielectrics including a specific dielectric capable of embedding components therein is separated into first and second portions that are respectively made up of sets of dielectrics on opposite sides of the specific dielectric. A first aid unit stores design information about placement of objects to the first portion, and manages and displays the design information according to a user command to aid in design of the first portion. A second aid unit stores design information about placement of objects to the second portion, and manages and displays the design information according to a user command to aid in design of the second portion. Further, the first and second aid units each store design information about placement of boundary objects which extend to both the first and second portions, and cooperatively manage the design information and each display it.