Abstract: Disclosed is a printed wiring board which attains aims of printed wiring boards required for realizing high-speed, high-frequency semiconductor devices, namely a printed wiring board having low dielectric constant, low dielectric loss tangent and low linear expansion coefficient. Also disclosed is a composite woven fabric suitably used as a base material for such a printed wiring board. Specifically disclosed is a composite woven fabric containing quartz glass fibers and polyolefin fibers, in which the ratio of the quartz glass fibers to the composite woven fabric is set at 10 vol % or more and 90 vol % or less. It is preferred that the quartz glass fibers each have a filament diameter of 3 ?m or more and 16 ?m or less, and the composite woven fabric has a thickness of 200 ?m or less.