To provide a helmet protective cover capable of easily setting a structure for protecting a helmet for a motorcycle at parking which is in storage by hooking a chin strap to a holder or a hook to be hung down, or a helmet for office security or home disaster prevention from rain, sand, dust or the like, light in weight and excellent in storage property, and easy in carrying.
The helmet protective cover simply comprises a cover body 1 composed of a sheet formed of a bag-shaped, light and thin waterproof material for wrapping a helmet body 5, an opening/closing part 3 formed at the cover body 1 for the access of a helmet, and a connection body 31 composed of a sheet formed of a waterproof material having a bellows-shaped part 27 in the middle thereof having a hollow part 30 for the access of a chin strap 6 of the helmet outside the cover. In addition, the tip of the connection body 31 is attachably/detachably held by a holding tool 24, a space between the chin strap 6 and the connection body 31 at the tip is narrowed to enhance waterproofness, and the helmet protective cover is lockable, and provided with a pocket for storage.