Provided is an electrostatic coating device and an electrostatic coating method each of which achieves a reduction in working hours and efficient coating at the time when a plurality of layers is coated with a plurality of colors. The electrostatic coating device of the present invention is characterized in that a coating material cartridge (10) includes: a plurality of coating-material containers (11, 12), a valve that makes a change of colors of coating materials, a common path (31) through which a plurality of coating materials is able to pass according to the change, and a cleaning circuit (33) that cleans up the common path (31); and the coating material cartridge (10) is configured to be removable from a coating machine. It is preferable that the coating material cartridge (10) of the present invention further include a plurality of individual paths (15, 16) each connected to each of the coating-material containers (11, 12) so that each one of the coating materials passes therethrough; and a plurality of valves (13, 14) each connected to the common path (31) and each of the individual paths (15, 16). It is preferable that each of the valves open and close a conduit line between the common path (31) and each of the coating-material containers corresponding thereto.