This disclosure relates to a thin pump including a case, a rotor, and a stator. The case has a bottom surface, a lower chamber, an upper chamber, and an accommodation space. The upper chamber is located further away from the bottom surface than the lower chamber. The upper chamber has two opposite ends respectively in fluid communication with the lower chamber and the accommodation space. The rotor includes an impeller and a magnet. The impeller is rotatably disposed in the lower chamber of the case. The magnet is disposed on the impeller. The stator is disposed in the case. The stator corresponds to the magnet of the rotor so as to drive the rotor to rotate with respect to the case.