To provide a catheter capable of excellently bending a distal end part and freely advancing to a body cavity branching at various angles.

For the catheter 10, a main lumen and a sub lumen 30 of a diameter smaller than the main lumen are formed inside a long-length tubular body (sheath 16) along the axis AX of the tubular body (sheath 16). Then, for the catheter 10, by pulling the proximal end part 17 of an operation wire 40 slidably inserted to the sub lumen 30 and fixed to the distal end part 15 of the catheter 10, the distal end part 15 of the catheter 10 is bent to the axis AX and turned around the axis AX.