A camera module, comprising: an imaging lens assembly; an image sensor disposed on an image surface of the imaging lens assembly; and an optical plate disposed between the imaging lens assembly and the image sensor, comprising: a substrate having an object-side surface and an image-side surface, the object-side surface facing towards an object side, the image-side surface facing towards an image side, and the object-side surface being parallel with the image-side surface; and at least one anti-reflection layer disposed on the image-side surface of the substrate, the at least one anti-reflection layer comprising a nanocrystal structure layer and an optical-connecting layer, wherein the nanocrystal structure layer comprises a metal oxide crystal, the optical-connecting layer connects the substrate and the nanocrystal structure layer, the nanocrystal structure layer is physically contacted with the optical-connecting layer, and an upper side of the optical-connecting layer is partly contacted with air; wherein a material refractive index of the nanocrystal structure layer is Nc, a material refractive index of the optical-connecting layer is Nf, a height of the nanocrystal structure layer is Hc, a thickness of the optical-connecting layer is Hf, a total height of the anti-reflection layer is H, and the following conditions are satisfied: Nf < Nc; Hf + Hc = H; and Hf < Hc. an imaging lens assembly; an image sensor disposed on an image surface of the imaging lens assembly; and an optical plate disposed between the imaging lens assembly and the image sensor, comprising: a substrate having an object-side surface and an image-side surface, the object-side surface facing towards an object side, the image-side surface facing towards an image side, and the object-side surface being parallel with the image-side surface; and at least one anti-reflection layer disposed on the image-side surface of the substrate, the at least one anti-reflection layer comprising a nanocrystal structure layer and an optical-connecting layer, wherein the nanocrystal structure layer comprises a metal oxide crystal, the optical-connecting layer connects the substrate and the nanocrystal structure layer, the nanocrystal structure layer is physically contacted with the optical-connecting layer, and an upper side of the optical-connecting layer is partly contacted with air; wherein a material refractive index of the nanocrystal structure layer is Nc, a material refractive index of the optical-connecting layer is Nf, a height of the nanocrystal structure layer is Hc, a thickness of the optical-connecting layer is Hf, a total height of the anti-reflection layer is H, and the following conditions are satisfied: Nf < Nc; Hf + Hc = H; and Hf < Hc. a substrate having an object-side surface and an image-side surface, the object-side surface facing towards an object side, the image-side surface facing towards an image side, and the object-side surface being parallel with the image-side surface; and at least one anti-reflection layer disposed on the image-side surface of the substrate, the at least one anti-reflection layer comprising a nanocrystal structure layer and an optical-connecting layer, wherein the nanocrystal structure layer comprises a metal oxide crystal, the optical-connecting layer connects the substrate and the nanocrystal structure layer, the nanocrystal structure layer is physically contacted with the optical-connecting layer, and an upper side of the optical-connecting layer is partly contacted with air; wherein a material refractive index of the nanocrystal structure layer is Nc, a material refractive index of the optical-connecting layer is Nf, a height of the nanocrystal structure layer is Hc, a thickness of the optical-connecting layer is Hf, a total height of the anti-reflection layer is H, and the following conditions are satisfied: Nf < Nc; Hf + Hc = H; and Hf < Hc.