A printed wiring board includes a core substrate including resin and inorganic fiber, a first buildup layer formed on a first surface of the substrate and including resin insulating layers and first conductive layers, and a second buildup layer formed on a second surface of the substrate on the opposite side of the core substrate with respect to the first surface and including resin insulating layers and second conductive layers. The first conductive layers in the first buildup have sum V1 of volumes which is greater than sum V2 of volumes of the second conductive layers in the second buildup, and the substrate has a first-surface side portion which has resin amount greater than resin amount of a second-surface side portion of the substrate where boundary between the first-surface and second-surface side portions is set with respect to the center line in the thickness direction of the substrate.