An electronic device includes an electronic component provided with leads. A printed circuit board has a front surface and a back surface and is provided with through holes and a groove hole. The through holes are capable of receiving the leads, respectively. The groove hole is formed so as to cross straight lines that connect the through holes. A first insulating spacer is provided on the groove hole between the leads so as to isolate the leads from each other and is positioned between the electronic component and the front surface of the printed circuit board. A second insulating spacer is inserted through the groove hole from the back surface of the printed circuit board and engages with the first insulating spacer so as to isolate end portions of the leads from each other.