A connection structure between a flat cable and an electronic circuit board includes an electronic circuit board; a cable connection hole formed to penetrate the electronic circuit board; a plurality of internal contacts provided on an inner surface of the cable connection hole; and a flat cable provided with a plurality of contacts which correspond to the plurality of internal contacts of the cable connection hole and are exposed to one side surface of the flat cable. When one end of the flat cable is inserted into the cable connection hole of the electronic circuit board, the plurality of contacts of the flat cable are in contact with the plurality of internal contacts of the cable connection hole, respectively.