To cut an inner surface of a pipe having a relatively small diameter.

A cutting apparatus includes: a rotating mechanism 3 for rotating a cutter 2 disposed inside the pipe; a turning mechanism 4 for causing the cutter 2 to circle around a predetermined axis S1; an axial movement mechanism 5 for moving the cutter 2 along an extending direction L of the axis S1; and a crossing direction movement mechanism 6 for moving the cutter 2 in a crossing direction of the axis S1. In the cutting apparatus, a rotative power transmission shaft 32 for transmitting power to the rotating mechanism 3 and a turning power transmission shaft 42 for transmitting power to the turning mechanism 4 are aligned concentrically on the axis S1.