An object of the present invention is to provide a printed wiring board which does not require arranging signal lines oblique to the warp or weft threads constituting a substrate and is capable of reducing a difference in transmission rates between the signal lines. The present invention relates to a printed wiring board including: an insulating layer; and a signal layer including a set of at least two signal lines and disposed on one side of the insulating layer. A substrate is embedded inside the insulating layer in such a manner to be further from the signal layer than a center of the insulating layer in a thickness direction of the insulating layer is. The insulating layer has a laminated structure of a thick layer, the substrate, and a thin layer. A ratio of a thickness of the thick layer to a thickness of the thin layer is greater than five.