METHOD OF MANUFACTURING WIRING BOARD

PROBLEM TO BE SOLVED: To provide a method of manufacturing a new wiring board capable of suppressing exudation of an insulation resin film (insulation layer) to be laminated and suppressing abnormality of a product characteristic according to formation of a step part due to the exudation in the case where a multilayer wiring board is manufactured in a build-up method.SOLUTION: An insulation layer supported by a support film is bonded on at least one main surface of a substrate in which a wiring pattern is formed on the at least one main surface by vacuum pressure press, so as to cover the wiring pattern. Next, after the support film is peeled from the insulation layer, an adhesion prevention film is bonded to the insulation layer. Next, planarization of the insulation layer is performed by performing planarization press to the substrate and the insulation layer through the adhesion prevention film.