To conceal an adhesive with an opaque function layer and to make the adhesive invisible from the transparent part of substrate by forming the adhesive within the range from the outer peripheral edge to the inner peripheral edge of the function layer and sticking a pair of the substrates to each other.

Groove parts 6a1, 6b1 are formed in the outer peripheral part and inner peripheral part of the first substrate 2 and groove parts 6a2, 6b2 in the outer peripheral part and inner peripheral part of the second substrate 3 to a toric shape. These groove parts 6a1, 6b1, 6a2, 6b2 store the adhesive 4 spreading more toward the transparent part on the inner peripheral side and more outer peripheral side than the function layers 5 at the time of sticking the first substrate 2 and the second substrate 3 after applying the adhesive 4. Since the application range is limited, the adhesive is applied within the range from the inner peripheral edge 5b to the outer peripheral edge 5a of the function layers 5. The adhesive 4 is applied within the range from the inner peripheral edge 5b to the outer peripheral edge 5a of the opaque function layers 5 in such a manner, thereby, the adhesives 4 are concealed by the function layers 5 without being made visible from the transparent part of the first substrate 2 and the second substrate 3.