To machine the end section of a steel pipe with small diameter without lowering machining accuracy.

Two tool posts 28 and 30 are arranged in the front face of a rotary disk 22 so as to be supported on a device body 14 pivotally so as to be able to move radially. Each of the tool posts 28 and 30 is provided with a turning arm 44 rotatably. The first arm section 44a of the turning arm 44 in the first tool post 28 is provided with a first cutting tool 48, to which an external end tip 46 formed so as to bevel and chamfer the external end section of the steel pipe and flatten the shaft end face of the steel pipe is secured. The first arm section 44a in the turning arm 44 of the second tool post 30 is provided with a second cutting tool 72, which is provided with a second tip 70 to bevel and chamfer the internal end section of the steel pipe. A copy roller 56 abutting on the external periphery is arranged rotatably at the first arm section 44a in each turning arm 44.