To provide a shield for bicycle helmets which is easily installed to a bicycle helmet to which a shield has not adhered.

A light-weight material of UV blocking such as a polycarbonate is prepared, and an attaching member such as a hook-and-loop fastener made detachable in the upper edge part is provided. A vent hole 4 is opened above the shield 1 for prevention of blur etc., and the shield 1 is made to cover up to the side of the face, and not to cut off the view by the seam etc., and the best use of the flexibility of the shielding material is made to fit the shield to helmets of individually different sizes and shapes.