The connection structure of flexible boards permits efficient positioning and connecting of a plurality of flexible boards arranged one over the other in a camera by providing a pair of pin elements in a protruding condition in a base portion and forming on one of the pin elements a groove to be engaged with flexible boards. A lens device includes a base metal sheet of metal and pin elements of plastic provided in a protruding condition in the base metal sheet. The pin element has a groove formed on an outer periphery surface of the opposite side to the pin element. A main flex or a shutter flex has holes formed therein, into which the pin elements are to be inserted. A spacing between the holes is formed a little smaller than a spacing between the pin elements.