An imaging device having a light-shielding area between a cover glass for imaging element and an optical member arranged adjacent to the cover glass, the light-shielding area having a light-transmitting area which is formed by a part of the light-shielding area on an edge of the optical member being cut off so that one or more corners on the boundary between an image area of the imaging element and the outside of the image area are locatable from the object side, and the following conditions (1) and (2) are satisfied:0.3≦a/IH≦1.5 (1)a1≦a≦a2′ (2)where, a1=IH−D tan θ1, a2′ denotes the smallest value of the following values a2, a3, and a4, a2=2b−IH−D tan θ2, a3=b−(D/2)×tan θ3, a4=b−X.