An electronic circuit having an electronic component mounted on a substrate, a light source device having the electronic circuit, and a method of manufacturing the electronic circuit on which the electronic component is mounted on the substrate are described. The electronic component has a plurality of lead pins to be electrically connected to wirings on the substrate. The substrate is formed with a hole having a larger dimension than a maximum distance between at least two lead pins of the lead pins. The lead pins are inserted into the hole from sides of tips of the lead pins while being bent at a plurality of bending portions, and fixed to the substrate by a solder.