A display apparatus is provided. The display apparatus is used for detecting an ultraviolet (UV) intensity. The display apparatus includes a lower-substrate, an upper-substrate and a processing unit. The lower-substrate includes a first, a second and a third photo sensors for detecting an intensity of the light in a first, a second and a third bands and converting the intensity of the light in the first, the second and the third bands into a first, a second and a third currents respectively, wherein the ranges of the second and the third bands are comprised within the range of the first band. The upper-substrate is disposed opposite to the lower-substrate. The processing unit is coupled to the first, the second and the third photo sensors, for receiving and processing the first, the second and the third currents so as to obtain the UV intensity.