The present invention provides a circuit board connecting structure enabled to obtain the reliable connection between circuit patterns by restricting the elongation of a flexible base material even when connecting portions are arranged in a face-to-face configuration and are press-contacted with each other. A circuit board connecting structure 10 includes a first circuit board 11, and a second circuit board 12. The circuit board connecting structure 10 is configured so that when a first connecting portion 13 and a second connecting portion 14 are sandwiched by a pair of pressing jigs 18, 19 and are press-contacted with each other, one 23 of first outer dummy terminals is accommodated between columns of ones 33, 33 of second outer dummy terminals, while the other first outer dummy terminal 24 is accommodated between columns of the other ones 34, 34 of the second outer dummy terminals.