The invention aims at providing a catheter and a balloon catheter preventing an outer layer from separating from an inner layer even in the case where the outer layer is pulled in an axis direction (distal end direction and proximal end direction). In a catheter 1, a reinforcing body 30 increases in diameter from a small diameter portion 31 toward a large diameter portion 33. The anchoring effect between an outer layer 40 and a wire 20 embedded therein, at the large diameter portion 33, can reduce a risk that the outer layer 40 is separated from the inner layer 10 even in the case where the outer layer 40 is pulled in an axis direction (distal end direction and proximal end direction) by a constricted portion or a blocked portion when the catheter 1 is inserted to a blood vessel, a bile duct, a pancreatic duct, or the like.
