To solve such problems that in a conventional cutting apparatus, its transportation in a construction site becomes a large scale, and also a certain storage space for it must be secured in the construction site.

A first frame 12 is longitudinally connected to a second frame 14, which has almost the same size as the first frame 12, via connecting means 22. A pipe W can be supported along the connected frames 12, 14. Rolling means 20 for making the pipe W roll in the peripheral direction of the pipe W are arranged on the first frame 12 and the second frame 14, respectively. A cutter means 18 is provided so as to be perpendicular to the longitudinal direction of the first frame 12 via a holder means 16 arranged at the second frame 14 side of the first frame 12 so as to be able to mount and dismount the cutter means 18.