To easily rotate a fuel cap, even if a ring member is not capable of rotating in an annular groove provided in a peripheral surface of a head part of the fuel cap due to freezing etc., in a connecting structure of the fuel cap provided with the ring member rotatably fitted into the annular groove to connect the ring member to a vehicle body such as a fuel lid via tether.

The ring member 3 is provided with a guide rail 31 extending along a peripheral direction. One end part of the tether 2 is connected to the vehicle body, while the other end part of the tether 2 is slidably connected to the guide rail 31.