To provide a method of manufacturing printed wiring board to obtain a printed wiring board including the vias of higher connection reliability and to lower a manufacturing cost.

The method comprises steps of forming via holes 8 in a core board 2 where a first conductor layer 4 and a second conductor layer 6 are formed on both surfaces of the board, forming a mask pattern of a resist 10 on surfaces of the first and second conductor layers 4, 6, covering the second conductor layer 6 with an insulation seal 12, filling the via holes 8 and forming a via 14 connected to the first conductor layer 4 by conducting electrolytic plating by feeding electric power to the second conductor layer 6, removing the insulation seal 12, forming an etching-resistant layer 18 on the surfaces of the first and second conductor layers 4, 6 exposed from the resist 10, removing the resist 10, and also removing, by etching, the first and second conductor layers 4, 6 exposed after the resist 10 is removed.