To provide a lightweight run-flat tire capable of continuously supporting the load of a vehicle and running to a safe place even when it is punctured and the internal pressure is reduced or lost and having pleasant comfortableness and low rolling resistance when the normal internal pressure is filled in it.

A side reinforcing layer (slant line section) having a nearly crescent cross sectional shape is provided toward the inside of the side region of a carcass layer 3, and a belt ply 6 exists as metal wire bundles arranged in parallel without being twisted. The metal wire bundles are arranged apart from each other in the width direction, and the thickness of an inner liner 4 is 0.1-0.3 mm in this run-flat travel radial tire.