An electrostatic atomizer 30 has a removably attachable canister 24. Once a paint bag 2 housed in the canister 24 exhausts, it is replaced by a new canister 24. Paint in a paint bag 2 is driven out by a mono pump 35 located in a pump segment 23 of the electrostatic atomizer 20. The mono pump 35 has a helical shaft 36 inside a paint feed tube 31. The mono pump 35 is driven by a servomotor via an insulating drive shaft 38. Paint in the paint bag 2 is drawn up when the helical shaft 36 rotates, and it is delivered to a bell cup 21 through the feed tube 31. Quantity of paint atomized by the bell cup 21 and interruption of the atomization are controlled by controlling the rotation of the mono pump 35.