Component built-in module, and manufacturing method for component built-in module

A manufacturing method for a component built-in module, including: forming, in a sheet member including resin, a via hole filled up with a conductive paste, a cavity in which an electronic component is to be built, and an adjustment space; and performing a heat press allowing the sheet member to abut against a substrate on which the electronic component has been mounted, wherein the adjustment space is formed so that a flow vector of the resin in a neighborhood of the via hole during the heat press, which is directed toward the electronic component, is cancelled by a flow vector of the resin in a neighborhood of the via hole during the heat press, which is directed toward the adjustment space.