To prevent an anticorrosive protective film applied to a branch line bar from being damaged when burying an anchor.

This underground anchor protective cover is used when burying the bar-shaped underground anchor having a spiral excavating blade on the tip side in the ground. A body of the underground anchor protective cover stores the branch line bar in an inside space for installing a branch line on the underground anchor, and can be stored in the space of a cylindrical anchor construction tool for rotating the underground anchor, and is constituted as a cylindrical body capable of detachably covering the branch line bar.