Provided is a connection structure body capable of detecting a break with ease and high accuracy and achieving high connection reliability and safety. A connection structure body 2 includes a first FFC (41), a stator side primary molding body (50), and a rotator side primary molding body (60) which are attached to both end portions (41A) and (41B) of the first FFC respectively and are able to make an electrical connection between the first FFC and the outside. The rotator side primary molding body 60 includes busbars (61-1a), (61-1b), (61-1c), and (61-1d) arranged in parallel to each other corresponding to busbars (51-la to 51-1d), a conductive portion (61-2) that electrically connects a pair of busbars (61-1a) and (61-1d) positioned on both ends respectively in the alignment direction of the busbars (61-1a to 61-1d), and a busbar case (62) for holding the busbars (61-1a to 61-1d) in such a manner that the busbars (61-1a to 61-1d) are partly exposed. The busbars (61-1a) and (61-1d) and the conductive portion (61-2) constitute an abnormality detection circuit by forming a part of a closed circuit.