To provide a highly reliable printed wiring board that has excellent adhesion between a conductor circuit and an inter-layer insulating resin and secures connection reliability between layers.

In a printed wiring board wherein an inter-layer insulating layer is formed on a conductor circuit of the substrate, a roughened surface is formed on the surface of the conductor circuit. The roughened surface has recesses with the maximum depth (Rmax) of 0.01 to 5 μm. If 0.01≤Pc<0.1 μm in the 2.5 mm length on the surface, wherein Pc is the height of irregularities, the count value is 300 or more and less than 30,000. The count value is 500 or more and less than 10,000 if 0.1≤Pc<1 μm.