To provide a pump miniaturized, reduced in weight, having excellent pumping performance and high reliability and reduced in noise, at a low cost, and to provide a tank suitable for supplying liquid fuel or the like using the pump.

A pump chamber 20 is formed on the inner peripheral side of a ring-shaped stator 10, and a rotor 23 with a magnetic substance 24 disposed along the inner periphery of the stator 10 is rotatably disposed in the pump chamber. An impeller is integrally formed at the rotor 23. The pump chamber 20 has an intake port 21 and a discharge port 22 for a fluid. A passage 31 is formed between an inner peripheral wall 45 of the pump chamber 20 and an outer peripheral part of the rotor 23 extending along the discharge port 22 from the intake port 21. A passage 31 extending along the intake port 21 from the discharge port 22 is closed, and the impeller is rotated together with the rotor 23 to discharge the fluid sucked from the intake port 21, from the discharge port 22.