An airless tire comprising: a tread ring having a tread, a hub located radially inside the tread ring, and cross radial members (5, 6, 20) connecting the tread ring with the hub and formed in the shape of a plate with a center line, a width in the tire circumferential direction and a thickness in the tire axial direction measured perpendicularly to the centerline, wherein the cross radial members (5, 6 20) include first radial members (5, 21) each extending from its first radially inner end (5a, 21a) to its first radially outer end (5b, 21b), and second radial members (6, 22) each extending from its second radially inner end (6a, 22a) to its second radially outer end (6b, 22b), the first radially inner ends (5a, 21a) and the second radially outer ends (6b, 22b) are positioned on one side in the tire widthwise direction, whereas the second radially inner ends (6a, 22a) and the first radially outer ends (5b, 21b) are positioned on the other side in the tire widthwise direction, and a first length measured along the center line of the first radial member (5, 21) from the first radially inner end (5a, 21a) to the first radially outer end (5b, 21b) is not more than 180 % of a distance measured in the tire radial direction between the hub and the tread ring, wherein the thickness (t1, t2) of each of the cross radial members (5, 6, 20) is constant along its entire extension from the hub to the tread ring, wherein each of the cross radial members (5, 6, 20) is curved in a tire meridian section including the radial member concerned, characterized in that the width of each of the cross radial members (5,6, 20) is partially decreased to have a constricted part within the range from the hub to the tread ring. a tread ring having a tread, a hub located radially inside the tread ring, and cross radial members (5, 6, 20) connecting the tread ring with the hub and formed in the shape of a plate with a center line, a width in the tire circumferential direction and a thickness in the tire axial direction measured perpendicularly to the centerline, wherein the cross radial members (5, 6 20) include first radial members (5, 21) each extending from its first radially inner end (5a, 21a) to its first radially outer end (5b, 21b), and second radial members (6, 22) each extending from its second radially inner end (6a, 22a) to its second radially outer end (6b, 22b), the first radially inner ends (5a, 21a) and the second radially outer ends (6b, 22b) are positioned on one side in the tire widthwise direction, whereas the second radially inner ends (6a, 22a) and the first radially outer ends (5b, 21b) are positioned on the other side in the tire widthwise direction, and a first length measured along the center line of the first radial member (5, 21) from the first radially inner end (5a, 21a) to the first radially outer end (5b, 21b) is not more than 180 % of a distance measured in the tire radial direction between the hub and the tread ring, wherein the thickness (t1, t2) of each of the cross radial members (5, 6, 20) is constant along its entire extension from the hub to the tread ring, wherein each of the cross radial members (5, 6, 20) is curved in a tire meridian section including the radial member concerned, characterized in that the width of each of the cross radial members (5,6, 20) is partially decreased to have a constricted part within the range from the hub to the tread ring.