The purpose of the present invention is to provide a catheter and a balloon catheter, wherein an outer layer is unlikely to separate from an inner layer even if the outer layer is pulled in the axial direction (direction toward front end and direction toward rear end) and in the radial direction (direction toward outer periphery). This catheter (1) is configured such that a gap (25) in a reinforcement layer (coil body) (30) is provided with a first joint (50) where a first inner layer protrusion (12) in which an inner layer (10) bites in a first outer layer (40) and a first outer layer protrusion (42) in which the first outer layer (40) bites in the inner layer (10) are engaged with each other. As a result, the area of the joint located in the gap (25) in the reinforcement layer (coil body) (30) and formed between the first outer layer (40) and the inner layer (10) increases to increase the joint strength between the first outer layer (40) and the inner layer (10). Also, an anchor effect by which the first joint (50) engages with the reinforcement layer (coil body) (30) can reduce the possibility of separation of the first outer layer (40) from the inner layer (10) even if the first outer layer (40) is pulled in the axial direction (direction toward front end and direction toward rear end) while the catheter (1) is curved.L'objectif de la présente invention est de fournir un cathéter et un cathéter à ballonnet, dans lequel une couche externe est peu susceptible de se séparer d'une couche interne même si la couche externe est tirée dans la direction axiale (direction vers l'extrémité avant et la direction vers l'extrémité arrière) et dans la direction radiale (direction vers la périphérie externe). Ce cathéter (1) est configuré de telle sorte qu'un espace (25) dans une couche de renforcement (corps de bobine) (30) est pourvu d'un premier joint (50) où une première saillie de couche interne (12) dans laquelle une couche interne (10) mord dans une première couche exter
