Fuel Tank Units

A fuel tank unit includes a lid member configured to close an opening formed on a fuel tank. The fuel tank also includes an upper unit attached to the lid member and including a combination valve device configured to be introduced into the fuel tank via the opening formed on the fuel tank and configured to function as an evaporated fuel control valve and a full limit valve. The lid member includes a cylindrical protective case configured to protect the combination valve device of the upper unit when the combination valve device is introduced into the fuel tank via the opening. The protective case is configured to entirely enclose an outer circumferential surface of the combination valve device with a space therebetween.