A connecting device comprising: a shaft; and a power supply cord having a power source plug to be connected to an outside power supply disposed at one end thereof; the connecting device being characterized by further comprising: a drum that has a container defined therein and is rotatably disposed on said shaft; a stator that is fixed to said shaft and is contained inside of said container; a rotator that is fixed to said drum, is rotatably disposed on said shaft, and is contained inside of said container with an interval with respect to said stator; first terminals (211, 213) that are disposed in said stator; second terminals (221, 224) that are disposed in said rotator and are brought into contact with said first terminals (211, 213), respectively; a connecting cord that is wound around said drum, and has a connecting plug to be connected to a vehicle at one end thereof whereas is electrically connected to said second terminals (221, 224) at the other end thereof; a leakage detector to be connected to the other end of said power supply cord and said first terminals (211, 213), and is contained inside of said container; a controller that is contained inside of said container, for controlling the drive of said leakage detector; a first signal terminal that is disposed in said stator and is electrically connected to said controller; and a second signal terminal that is disposed in said rotator, is brought into contact with said first signal terminal, and is electrically connected to said connecting plug; wherein said stator and said rotator are arranged in such a manner that their end surfaces arranged in the axial direction of said shaft face each other; said first terminals (211, 213) and said first signal terminal are disposed in said stator at the end surface facing said rotator, serving as an annular metallic ring annularly extending on said shaft; said second terminals (221, 224) and said second signal terminal are disposed in said rotator at the end surface facing said stator; and said first signal terminal is positioned outward of said first terminals (211, 213) whereas said second signal terminal is positioned outward of said second terminals (221, 224). a shaft; and a power supply cord having a power source plug to be connected to an outside power supply disposed at one end thereof; the connecting device being characterized by further comprising: a drum that has a container defined therein and is rotatably disposed on said shaft; a stator that is fixed to said shaft and is contained inside of said container; a rotator that is fixed to said drum, is rotatably disposed on said shaft, and is contained inside of said container with an interval with respect to said stator; first terminals (211, 213) that are disposed in said stator; second terminals (221, 224) that are disposed in said rotator and are brought into contact with said first terminals (211, 213), respectively; a connecting cord that is wound around said drum, and has a connecting plug to be connected to a vehicle at one end thereof whereas is electrically connected to said second terminals (221, 224) at the other end thereof; a leakage detector to be connected to the other end of said power supply cord and said first terminals (211, 213), and is contained inside of said container; a controller that is contained inside of said container, for controlling the drive of said leakage detector; a first signal terminal that is disposed in said stator and is electrically connected to said controller; and a second signal terminal that is disposed in said rotator, is brought into contact with said first signal terminal, and is electrically connected to said connecting plug; a drum that has a container defined therein and is rotatably disposed on said shaft; a stator that is fixed to said shaft and is contained inside of said container; a rotator that is fixed to said drum, is rotatably disposed on said shaft, and is contained inside of said container with an interval with respect to said stator; first terminals (211, 213) that are disposed in said stator; second terminals (221, 224) that are disposed in said rotator and are brought into contact with said first terminals (211, 213), respectively; a connecting cord that is wound around said drum, and has a connecting plug to be connected to a vehicle at one end thereof whereas is electrically connected to said second terminals (221, 224) at the other end thereof; a leakage detector to be connected to the other end of said power supply cord and said first terminals (211, 213), and is contained inside of said container; a controller that is contained inside of said container, for controlling the drive of said leakage detector; a first signal terminal that is disposed in said stator and is electrically connected to said controller; and a second signal terminal that is disposed in said rotator, is brought into contact with said first signal terminal, and is electrically connected to said connecting plug; wherein said stator and said rotator are arranged in such a manner that their end surfaces arranged in the axial direction of said shaft face each other; said first terminals (211, 213) and said first signal terminal are disposed in said stator at the end surface facing said rotator, serving as an annular metallic ring annularly extending on said shaft; said second terminals (221, 224) and said second signal terminal are disposed in said rotator at the end surface facing said stator; and said first signal terminal is positioned outward of said first terminals (211, 213) whereas said second signal terminal is positioned outward of said second terminals (221, 224).