A fuel supply apparatus is configured to feed a fuel supplied from a filler port through a filler file to a fuel tank. A grid member that is configured to allow for insertion into a fuel passage formed by the filler pipe and move along the fuel passage and serve to prevent suction of the fuel is held at a placement site in the filler pipe. The placement site is provided at a higher position in a vertical direction than a liquid level of the fuel in the filler pipe. This configuration enhances the effectiveness for preventing suction of the fuel from the filler pipe.

An improved, secure, anti-siphoning method and apparatus that can be fitted into any size fuel tank. The present invention includes a re-configured fuel cap that includes an electronic display, a touchpad for numerically inputting a security code for allowing a user to unscrew the fuel cap. In addition, a biometric reader is implemented to read a user's thumb print, and subsequently allowing the user to access the fuel tank.