A method of manufacturing a flex-rigid wiring board including disposing a flexible board comprising a flexible substrate and a conductor pattern formed over the flexible substrate and a non-flexible substrate adjacent to each other, covering a boundary between the flexible board and the non-flexible substrate with an insulating layer comprising an inorganic material, providing a conductor pattern on the insulating layer, forming a via hole opening which passes through the insulating layer and reaches the conductor pattern of the flexible board, and plating the via hole opening to form a via connecting the conductor pattern of the flexible board and the conductor pattern on the insulating layer.