PURPOSE: To improve comfortable feeling and the driving stability of a non- pneumatic tire used as a sparetire.

CONSTITUTION: A circular part 3 is provided at the external peripheral edge of a disc 2 attached to a tire shaft and a tire base body formed in one body by use of plastics is provided. The circular part 3 is attached at both sides of tire shaft and opend at radially different positions respectively. And further it is provided with circumferential side grooves 7A, 7B extending in the peripheral direction and circular supports 9 of an elastic material which contact both inner peripheral face F1 and outer peripheral face F2 in the radial direction of the circumferential side grooves 7A, 7B are arranged inside the circumferential side grooves 7A, 7B and further, a tread rubber 5 is stuck at the outer peripheral face of the circular part 3.