Abstract: A mounting structure of a connector 6 for use with a circuit board 7 includes fixing parts 8 provided on one side of the connector 6 and fixed to the circuit board 7, terminals 25 contained in the connector and connected to the circuit board by soldering, a plurality of wiring boards 41 to 42 arranged adjacent to the circuit board, and a pair of support walls 9 provided on the other side of the connector 6 and projected from the connector. The support walls 9 are abutted at their lower ends against the uppermost wiring board 41, enabling the connector to be supported by both the support walls 9 and the fixing parts 8. The fixing parts 8 and the support walls 9 are projected in directions intersecting at a right angle so that the support walls 9 may be abutted against the wiring board 41 in an engaging direction of a mating connector 37. The support walls 9 are projected longer than the terminals 25 toward the wiring board 41.