An object of the present invention is to provide a catheter capable of tip deflection operation which has excellent blood vessel followability while ensuring flatness of shape change of the tip portion. A catheter shaft having a first lumen 11L and a second lumen 12L having a distal end flexible portion 10A, a first lumen 11L, a first manipulation wire 41, a second manipulation wire 42, and a first manipulation wire 41L. Two high-strength rod-shaped members 51 and 52 embedded in the constituent resin of the catheter shaft 10 so as to have respective central axes on the two virtual planes (P2) and face each other with the central axis of the catheter shaft 10 interposed therebetween. In the three-point bending test performed on the catheter shaft 10 having the rod-shaped members 51 and 52 embedded therein, the load when deflected by 1 mm along the first virtual plane (P1) is (F1), and the second virtual plane ( When the load when deflected by 1 mm along P2) is (F2), the ratio of (F2) / (F1) is 1.0 to 3.5. [Selection] Figure 2【課題】先端部分の形状変化の平面性を確保しながら血管追従性に優れた先端偏向操作可能カテーテルを提供すること。【解決手段】先端可撓部分１０Ａを有し、対向配置された第１ルーメン１１Ｌおよび第２ルーメン１２Ｌを有するカテーテルシャフト１０と、第１操作用ワイヤ４１と、第２操作用ワイヤ４２と、第２仮想平面（Ｐ２）上に各々の中心軸を有し、カテーテルシャフト１０の中心軸を挟んで対向するよう、カテーテルシャフト１０の構成樹脂中に埋設された高強度の棒状部材５１，５２とを有し、棒状部材５１，５２が埋設されたカテーテルシャフト１０について行う３点曲げ試験において、第１仮想平面（Ｐ１）に沿って１ｍｍ撓ませたときの荷重を（Ｆ１）、第２仮想平面（Ｐ２）に沿って１ｍｍ撓ませたときの荷重を（Ｆ２）とするとき、（Ｆ２）／（Ｆ１）の比率が１．０～３．５である。【選択図】 図２
