A balloon catheter (10) has a hub (20) provided on the proximal end side thereof and has a balloon (40) provided on the distal end side thereof. The balloon catheter (10) comprises: a hypo-tube (31) provided with a section (31b) in which a cutout is formed and which is located on the distal end side of the hypo-tube (31) an outer tube (32) which has a proximal end joined to the hypo-tube (31) at a position located further toward the proximal end side than the section (31b), which has the cutout formed therein, of the hypo-tube (31), the outer tube (32) extending further toward the distal end side from the portion (32a) at which the outer tube (32) is joined to the hypo-tube (31) than the hypo-tube (31) and a core wire (33) inserted toward the distal end side from an adjacent section (31a1) adjacent to a start point, the insertion being through the inner cavity of the hypo-tube (31) and the inner cavity of the outer tube (32). The core wire (33) is secured to the hypo-tube (31) at the adjacent section (31a1). The balloon catheter is configured so that a portion at which the hardness suddenly increases does not occur in the cutout section and the core wire can be satisfactorily secured to the hypo-tube.Linvention concerne un cathéter à ballonnet (10) qui a un embout (20) disposé sur le côté dextrémité proximale de celui-ci et a un ballonnet (40) disposé sur le côté dextrémité distale de celui-ci. Le cathéter à ballonnet (10) comprend : un hypo-tube (31) comportant une section (31b) dans laquelle une découpe est formée et qui est située sur le côté dextrémité distale de lhypo-tube (31) un tube externe (32) qui a une extrémité proximale assemblée à lhypo-tube (31) à une position située en étant plus éloignée vers le côté dextrémité proximale que la section (31b), qui a la découpe formée dans celle-ci, de lhypo-tube (31), le tube externe (32) sétendant en étant plus éloigné vers le côté dextrémité distale à partir de la partie (32a) à laquelle le tube externe (32) est as
