Abstract: The discharge lamp comprises: an arc tube including electrodes disposed at both ends of a glass tube; and bases provided at the two ends of the glass tube and supplying power to the electrodes. The arc tube includes two spiral parts, extending from the middle part of the glass tube to both end parts thereof, circularly winding around an imaginary axis and progressively away from the imaginary axis as shifted in a direction from the middle part toward the end parts. The end parts of the glass tube are attached by a silicon resin to adjacent parts of the glass tube, which are located on the imaginary axis side in relation to the end parts.