Provided are a catheter that prevents a shaft from flattening after pressurization and is highly slidable, and a method for producing the catheter. A catheter (1) having a distal side and a proximal side comprises a shaft (2) having an outer cylinder member (4) and having an interpolation member (3), at least a portion of which in the axial direction being disposed in the outer cylinder member (4), wherein: the outer cylinder member (4) and/or interpolation member (3) is a multilayer tube having a first layer (31) and a second layer (32) laminated with the first layer (31)； the ratio of the cross sectional area of the second layer (32) to the cross sectional area of the first layer (31) in a cross section orthogonal to the axial direction of the multilayer tube is no more than 0.7； the material constituting the second layer (32) includes a material having a higher degree of crystallinity and a lower melting point than the material constituting the first layer (31)； and the initial roundness calculated by the equation below is at least 92% in a cross section orthogonal to the axial direction of the multilayer tube. Initial roundness (%) = (Short axis outer diameter of multilayer tube/Long axis outer diameter of multilayer tube) x 100La présente invention concerne un cathéter qui empêche un arbre de s'aplatir après mise sous pression et est hautement coulissant, et un procédé de production du cathéter. Un cathéter (1) ayant un côté distal et un côté proximal comprend un arbre (2) ayant un élément de cylindre externe (4) et ayant un élément d'interpolation (3), dont au moins une partie dans la direction axiale est disposée dans l'élément de cylindre externe (4), l'élément de cylindre externe (4) et/ou l'élément d'interpolation (3) étant un tube multicouche ayant une première couche (31) et une seconde couche (32) stratifiée avec la première couche (31) ； le rapport de la surface de section transversale de la seconde couche (32) sur la section transversale de la premièr
