Provided is a prepreg capable of attaining thermal expansion coefficient reduction and elastic modulus increase without increasing the filling ratio of an inorganic filler therein and/or without using a resin having a low thermal expansion coefficient, and thereby capable of reducing warpage thereof. Specifically, provided is a prepreg containing glass fibers and a thermosetting resin composition, and containing a layer of plural glass fiber filaments aligned to run nearly parallel to each other in one direction. Also provided are a production method for the prepreg, a laminate containing the prepreg and its production method, a printed circuit board containing the laminate, and a semiconductor package having a semiconductor device mounted on the printed circuit board.