To provide a catheter enabling a tip deflecting operation which comprises a compact operation part with excellent operability, where wires for an operation are prevented from being protruded by the looseness of the wires and an operation force is reduced.

The turning knob 7 of the catheter enabling the tip deflecting operation includes: at least one first projection 54a which is turned with the rotary handle 7 when the rotary handle 7 is turned in a first direction, is brought into contact with the proximal end of the wire 30a for a first operation, and absorbs the looseness in the neighborhood of the proximal end of the first operation wire 30a; and at least one second projection 54b which is turned with the turning knob 7 when the turning knob 7 is rotated in a second direction, is brought into contact with the proximal end of the wire 30b for a second operation, and absorbs the looseness in the neighborhood of the proximal end of the second operation wire 30b.