Method for manufacturing electronic component embedding substrate and electronic component embedding substrate

The present invention relates to a method for manufacturing an electronic component embedding substrate and an electronic component embedding substrate. According to one embodiment of the present invention, a method for manufacturing an electronic component embedding substrate includes a step of inserting an electronic component into a cavity formed in a core substrate; a step of stacking a first insulating layer on one side of the core substrate inserted into the electronic component; a step of improving the surface profile of the exposed surface of at least the first insulating layer by performing surface treatment on the other side of the core substrate opposite to the stacking direction of the first insulating layer; and a step of stacking a second insulating layer on the other side of the core substrate by touching the exposed surface of the first insulating layer having improved surface profile. Also, suggested is an electronic component embedding substrate.