Provided are a substrate for mounting an electronic element and an electronic device which make it possible to improve impact resistance. A substrate 1 for mounting an electronic element according to one embodiment of the present invention comprises: a first wiring board 2 in a quadrangular frame shape an inside portion of the first wiring board serving as a first through hole 2a; a second wiring board 6 in a quadrangular frame shape or plate shape, the board being provided so as to be overlapped by the lower surface of the first wiring board 2, having one side of an outer edge of the second wiring board located further outward than one side corresponding to an outer edge of the first wiring board 2, and being electrically connected to the first wiring board 2; a metal plate 4 provided so as to be overlapped by the lower surface of the second wiring board 6 so as to sandwich the second wiring board 6 between itself and the first wiring board 2, and having an outer edge located further outward than the outer edge of the first wiring board 2 and located further inward than the one side of the outer edge of the second wiring board 6; and a lens holder 5, which is a cover body that is fixed to an outer peripheral portion of the metal plate 4 by sandwiching a portion of the one side of the outer edge of the second wiring board 6, so as to cover the first wiring board 2 and the second wiring board 6. The inside of the frame of the first wiring board 2, or the inside of the frame of the first wiring board 2 and the second wiring board 6, serves as an electronic element mounting space 11.