A UV-A, UV-B discriminating sensor provided with a photochromic compound or photochromic composition as the sensor portion, the photochromic compound or photochromic composition coloring under exposure to UV of wavelength greater than or equal to 280 nm or less than or equal to 400 nm, and wherein at least a portion of the photochromic layer is covered with a layer containing a pigment which absorbs UV of wavelength less than 320 nm, or with a layer containing a pigment which absorbs UV of a wave length greater than or equal to 320 nm but less than or equal to or equal to 400 nm.
