Provided are a printed wiring board and a flexible printed wiring board which hardly generate radiation electromagnetic noises and are not easily affected by external noises. First and second wave-shape wirings are provided between at least two insulation substrates stacked on each other. The first and the second wave-shape wirings three-dimensionally intersect with each other in a plane direction and a thickness direction of the insulating substrates. The first and second wave-shape wirings are electrically separated from each other by a resist layer provided between the insulating substrates.