A rotary connector device including a stator and a rotator rotatably attached to the stator, the rotary connector device comprising a connection structure body including a flexible flat cable housed in windable and unwindable manners in an annular space (S1) between the stator and the rotator , and a first connection tool that is attached to one end of the flexible flat cable configured to make an electrical connection between the flexible flat cable and outside of the rotary connector device, wherein the first connection tool includes: a first plurality of busbars (61-1a to 61-1d) arranged in parallel to each other; a conductive portion (61-2) configured to electrically connect a pair of busbars (61-1a, 61-1d) positioned on both ends respectively in an alignment direction of the first plurality of busbars (61-1a to 61-1d); a first holding portion configured to hold the first plurality of busbars (61-1a to 61-1d) in such a manner that the first plurality of busbars are partly exposed, wherein the pair of busbars (61-1a, 61-1d) and the conductive portion (61-2) form a part of a closed circuit, thereby constituting an abnormality detection circuit, characterised in that , the rotary connector device further comprises at least another flexible flat cable wound on an outer peripheral side of the flexible flat cable in the annular space (S 1), wherein a length of the flexible flat cable that constitutes the abnormality detection circuit is shorter than any length of the at least another flexible flat cable in the annular space (S 1). the rotary connector device comprising a connection structure body including a flexible flat cable housed in windable and unwindable manners in an annular space (S1) between the stator and the rotator , and a first connection tool that is attached to one end of the flexible flat cable configured to make an electrical connection between the flexible flat cable and outside of the rotary connector device, wherein the first connection tool includes: a first plurality of busbars (61-1a to 61-1d) arranged in parallel to each other; a conductive portion (61-2) configured to electrically connect a pair of busbars (61-1a, 61-1d) positioned on both ends respectively in an alignment direction of the first plurality of busbars (61-1a to 61-1d); a first holding portion configured to hold the first plurality of busbars (61-1a to 61-1d) in such a manner that the first plurality of busbars are partly exposed, wherein a first plurality of busbars (61-1a to 61-1d) arranged in parallel to each other; a conductive portion (61-2) configured to electrically connect a pair of busbars (61-1a, 61-1d) positioned on both ends respectively in an alignment direction of the first plurality of busbars (61-1a to 61-1d); a first holding portion configured to hold the first plurality of busbars (61-1a to 61-1d) in such a manner that the first plurality of busbars are partly exposed, wherein the pair of busbars (61-1a, 61-1d) and the conductive portion (61-2) form a part of a closed circuit, thereby constituting an abnormality detection circuit, characterised in that , the rotary connector device further comprises at least another flexible flat cable wound on an outer peripheral side of the flexible flat cable in the annular space (S 1), wherein a length of the flexible flat cable that constitutes the abnormality detection circuit is shorter than any length of the at least another flexible flat cable in the annular space (S 1). <EOS>