A method of manufacturing an electronic component (400; 500; 500A-C), comprising the steps of: a) forming a plurality of wiring boards (100, 200; 300) each comprising a semiconductor substrate (101, 201, 301), said step (a) comprising: (i) providing the semiconductor substrates (101, 201, 301), (ii) forming first through holes (101A, 201A; 301A) penetrating through the respective semiconductor substrates (101, 201; 301), (iii) forming a second through hole, which is formed along with the first through holes, in any of the semiconductor substrates (101, 201,301), (iv) forming a recess portion (301 C) for mounting an electronic element in said semiconductor substrate which comprises the second through hole, wherein the recess portion is formed such that the second through hole is arranged in a bottom of the recess portion; and (v) filling a conductive material (104, 204, 305; 306) in the first and second through holes; b) providing conductive projections (107; 310, 311) on the conductive material filled in the first and second through holes of any of the plurality of wiring boards; c) mounting the electronic element in the recess portion to connect the electronic element to the conductive material filled in the second through hole by the conductive projection provided on the second through hole; and d) bonding, by pressing and heating, the plurality of wiring boards to each other and electrically connecting the conductive material (104, 204, 305) of the respective wiring boards by the projections (107, 310) provided on the first through holes (101A, 201A; 301A), wherein the electronic element is sealed in the recess portion as a result of the plurality of wiring boards (100, 200, 300) being bonded together. a) forming a plurality of wiring boards (100, 200; 300) each comprising a semiconductor substrate (101, 201, 301), said step (a) comprising: (i) providing the semiconductor substrates (101, 201, 301), (ii) forming first through holes (101A, 201A; 301A) penetrating through the respective semiconductor substrates (101, 201; 301), (iii) forming a second through hole, which is formed along with the first through holes, in any of the semiconductor substrates (101, 201,301), (iv) forming a recess portion (301 C) for mounting an electronic element in said semiconductor substrate which comprises the second through hole, wherein the recess portion is formed such that the second through hole is arranged in a bottom of the recess portion; and (v) filling a conductive material (104, 204, 305; 306) in the first and second through holes; (i) providing the semiconductor substrates (101, 201, 301), (ii) forming first through holes (101A, 201A; 301A) penetrating through the respective semiconductor substrates (101, 201; 301), (iii) forming a second through hole, which is formed along with the first through holes, in any of the semiconductor substrates (101, 201,301), (iv) forming a recess portion (301 C) for mounting an electronic element in said semiconductor substrate which comprises the second through hole, wherein the recess portion is formed such that the second through hole is arranged in a bottom of the recess portion; and (v) filling a conductive material (104, 204, 305; 306) in the first and second through holes; b) providing conductive projections (107; 310, 311) on the conductive material filled in the first and second through holes of any of the plurality of wiring boards; c) mounting the electronic element in the recess portion to connect the electronic element to the conductive material filled in the second through hole by the conductive projection provided on the second through hole; and d) bonding, by pressing and heating, the plurality of wiring boards to each other and electrically connecting the conductive material (104, 204, 305) of the respective wiring boards by the projections (107, 310) provided on the first through holes (101A, 201A; 301A), wherein the electronic element is sealed in the recess portion as a result of the plurality of wiring boards (100, 200, 300) being bonded together.