A optical element prevents a contaminant component adhering to the edge thereof from spreading through the capillary action and thus from forming a stain. A display device includes the element. An optical element includes a front surface provided with projected portions at a pitch equal to or shorter than the wavelength of visible light, the front surface having a contact angle with water of 100° or greater at least at an edge and preferably having a contact angle with hexadecane of 20° to 100° at least at an edge. A display device includes such an optical element.