The invention relates to a blood pump. The blood pump comprises a flexible drive shaft (3) guided in a catheter, a conveying element (6) connected to the drive shaft (3) in a distal region of the drive shaft (3), and a motor (7), wherein the motor (7) has a stator (36) and a rotor (30) mounted such that it can move in the stator (36). The stator (36) comprises a winding (37) and the rotor (30) comprises a rotor magnet (31). In addition, the drive shaft (3) is connected to the rotor (30) at a proximal end of the drive shaft (3). The stator (36) and the rotor (30) are nondetachably connected to one another, and form a gap (40) with a ring-shaped cross-section, which is delimited by the rotor (30) and the stator (36).