A present invention provides a method for manufacturing a printed wiring board having excellent plating adhesion to a resin substrate having low surface roughness such as having surface roughness Ra of 0.2 μm or less, having excellent treating solution stability, and having high penetrability into the resin substrate. The method for manufacturing a resin substrate includes a step 1A or a step 1B; and a step 2 after the step 1A or the step 1B; and the steps are conducted before conducting electroless plating.