An electronically commutated external rotor motor, which includes: a bearing tube; an internal stator, which is arranged on the bearing tube; a bell-shaped external rotor having a rotor bell, which external rotor is separated by a magnetically active air gap from the internal stator and has a rotor base, wherein fan blades can be arranged on the outside of the rotor bell; a shaft associated with the external rotor, which is rotatably mounted in the bearing tube; which bearing tube has a rotor-proximal section, which extends in the axial direction up into the region of the rotor base. and which bearing tube has a rotor-remote section, which extends in the axial direction away from the rotor-proximal section; a flange provided on the rotor-remote section of the bearing tube; and a seal element provided with a seal lip, which element is arranged between the flange and the outer rotor, wherein the seal lip interacts with the rotor bell, and wherein a printed circuit board is arranged between the internal stator and the flange, wherein the seal element is introduced into a seat, which is radially circumferential on an outside at a flange end of the end region of the flange facing toward the internal stator, between an extension formed by the rotor bell and the flange end, and the seal lip is formed as a flexible lip extending radially diagonally outward, which presses against a radial inside of the extension, wherein, during operation of the motor, the seal lip is pressed by a pressure difference (p2 - p1) generated by means of the fan blades against the inside of the extension, and wherein no moisture or dust can penetrate from the outside into the motor, since the seal lip is pressed against the extension. a bearing tube; an internal stator, which is arranged on the bearing tube; a bell-shaped external rotor having a rotor bell, which external rotor is separated by a magnetically active air gap from the internal stator and has a rotor base, wherein fan blades can be arranged on the outside of the rotor bell; a shaft associated with the external rotor, which is rotatably mounted in the bearing tube; which bearing tube has a rotor-proximal section, which extends in the axial direction up into the region of the rotor base. and which bearing tube has a rotor-remote section, which extends in the axial direction away from the rotor-proximal section; a flange provided on the rotor-remote section of the bearing tube; and a seal element provided with a seal lip, which element is arranged between the flange and the outer rotor, wherein the seal lip interacts with the rotor bell, and wherein a printed circuit board is arranged between the internal stator and the flange, wherein the seal element is introduced into a seat, which is radially circumferential on an outside at a flange end of the end region of the flange facing toward the internal stator, between an extension formed by the rotor bell and the flange end, and the seal lip is formed as a flexible lip extending radially diagonally outward, which presses against a radial inside of the extension, wherein, during operation of the motor, the seal lip is pressed by a pressure difference (p2 - p1) generated by means of the fan blades against the inside of the extension, and wherein no moisture or dust can penetrate from the outside into the motor, since the seal lip is pressed against the extension.