The invention provides a technique for providing a medical device having good operability. The invention relates to a catheter 100 which includes a tubular body 10 which includes main lumen 20 and sub-lumen 80 which is disposed around the main lumen 20 and extends along the longitudinal direction of the main lumen 20 and an operating line 70 which distal end is fixed to the distal end of the tubular body 10. A cross section of operation wire 70 in the direction perpendicular to the longitudinal direction is circular, or a cross-section of a stranded wire composed of a plurality of thin wires and is circular in cross-section perpendicular to the longitudinal direction. The cross-section of sub-lumen (80a, 80b) in the direction perpendicular to the longitudinal direction is an oblate circle shape in the circumferential direction of the main lumen 20.本發明提供一種技術,以提供操作性良好之醫療機器。本發明之導管100包含:管狀本體10,其形成有主腔20、及配置於主腔20之周圍且沿著上述主腔20之長邊方向延伸之副腔80;及操作線70,其配置於副腔80內,且其遠位端固定於上述管狀本體10之遠位端。操作線70係與上述長邊方向正交之剖面為圓形者,或操作線70係以與上述長邊方向正交之剖面為圓形之複數條細線構成之絞合線。與上述長邊方向正交之副腔80(80a、80b)之剖面形狀係於上述主腔20之周向上成扁平之扁平形狀。11‧‧‧內層12‧‧‧外層20‧‧‧主腔50‧‧‧塗層70‧‧‧操作線80‧‧‧副腔82‧‧‧中空管100‧‧‧導管A‧‧‧長度B‧‧‧長度
