To obtain a helmet cover capable of protecting the surface of helmet in wearing the helmet.

This helmet cover 6 is formed of stretchable fabric and is equipped with a helmet cover front opening 7 covering the upper part and the right and left parts of a helmet front opening 4 so as to catch these parts therein, a hook 8 of hook-and-loop fasteners as an engaging part provided on the rear of the upper part and right and left parts of the helmet cover front opening 7 and a helmet cover inferior surface opening 10 covering the rear of helmet cover inferior surface opening 10 so as to enwrap the rear therein. Thereby, the helmet cover can be covered even in wearing the helmet.