Provided is a substrate with a built-in electronic component that can avoid as much as possible the occurrence of malfunctions in the electronic component due to moisture entering, even when an electronic component, provided with a structure in which a terminal pad is present where a hole in the sealing part provided on the main body of a component is located, is built into the substrate. A SAW filter 12 built into a substrate 11 is provided with a structure that has terminal pads 12c to 12e on the bottom of respective holes 12f1 in a sealing part 12f. The lower surfaces of respective conductive vias 11d2 are connected to the upper surfaces of the terminal pads 12c to 12e through the respective holes 12f1 such that a ring-shaped gap CC is formed between outer surfaces of the conductive vias 11d2 and inner surfaces of the holes 12f1. Each ring-shaped gap CC is filled with a part that is integral with a first insulating layer 11c.