Disclosed herein is a manufacturing method of a circuit board. The manufacturing method includes a first step for preparing a prepreg in which a core material is impregnated with an uncured resin. The prepreg has a through-hole surrounded by the core material and the resin so as to penetrate through the core material and the resin. The manufacturing method further includes a second step for housing a semiconductor IC in the through-hole, and a third step for pressing the prepreg so that a part of the resin flows into the through-hole to allow the semiconductor IC housed in the through-hole to be embedded in the resin.