To provide a cutting and polishing device and an execution method which employs the device which can cut or polish cylindrical body or a plane body in a vertical condition as well as in a horizontal condition with high efficiency.

In this cutting and polishing device 1, a high pressure water nozzle 4 or a polishing member, a running wheel 5 of a magnetic body rolling in contact by an arm capable of turning in the direction vertical to a guide rail face 3, and a drive motor of the running wheel 5 are provided for a device main body mounted on a beltlike guide rail 3 provided along an object to be constructed so as to travel freely. Moreover, in the execution method employing this device 1, the object to be executed is cut or polished by providing the beltlike guide rail 3 along the direction of cutting or polishing of the object to be executed and mounting the cutting and polishing device 1 on this beltlike guide rail 3.