Collation and welding of card component sheets can be performed in a simple facility. Plastic cards such as IC cards having substantially no distortion and twisting are provided. A round hole (17) and an ellipse hole (18) are formed at the corresponding positions in layered component sheets (19a to 19d), and positioning pins (21) are inserted and passed through respective holes. Since at this occasion, the ellipse hole (18) has play relative to the positioning pin (21), the distortion and twisting of each card component sheet can be adsorbed, and the appearance can be improved by avoiding printing dislocation and the like. It is also able to prevent mechanical strength from lowering due to residual stress.