An electric arc spraying system includes a spraying gun for thermally spraying an inner surface of an object such as a cylinder block by blasting compressed gas substantially perpendicularly to the supplying direction of target wires. The spraying gun is rotated by a spraying gun rotation mechanism. The target wires are loaded in and supplied from wire supplying sources. A wire feeder rotation mechanism is provided for rotating the wire supplying sources synchronously with the spraying gun in rotation. Wire feeders are provided at the spraying gun or adjacent to the wire supplying sources for feeding the target wires. Wire support cables are configured to guide the target wires from the wire supplying sources to the spraying gun.