Method for manufacturing substrate with built-in component, and substrate with built-in component

This method for manufacturing a substrate with a built-in component comprises: a step for providing an intermediate member (2) provided with an electronic component (10), the first surface (13) of which is provided with a first electrode (11), and a first conductive layer (20) provided on the first surface (13) of the electronic component (10) so as to cover the first electrode (11); and a step for forming a first insulating resin layer (40) on the first surface (3) of the intermediate member (2). The first conductive layer (20) has: a first cured adhesive layer (23) containing a cured adhesive layer (22) containing conductive particles (21) and a cured adhesive composition; and a first metal foil layer (24) disposed on the surface of the first curable adhesive layer (23) on the opposite side from the electronic component (10). The conductive particles (21) of the first cured adhesive layer (23) electrically connect the first electrode (11) of the electronic component (10) and the first metal foil layer (24).