Patent ID: 7543374

Claim:
A method of manufacturing a wiring substrate, comprising the steps of: preparing a temporary substrate made of a nonwoven glass fabric impregnated with resin and preparing a metal foil; tentatively fixing the metal foil onto at least one surface of the temporary substrate by selectively attaching a peripheral side of the metal foil to a peripheral portion of a wiring formation region on the temporary substrate with an adhesive layer, wherein there is no adhesive layer in a center principal portion of the metal foil; and the metal foil is simply in contact with the temporary substrate at the center principal portion, whereby the center principal portion of the metal foil is easily separable from the temporary substrate later; forming a build-up wiring layer on the metal foil; and obtaining a wiring member in which the build-up wiring layer is formed on the metal foil, by cutting out an inside portion of a structure in which the metal foil and the build-up wiring layer is formed on the temporary substrate, the portion being inward from the adhesive layer formed therein, and thus by separating the metal foil from the temporary substrate.