A method for forming a coating film on a powder includes: a dispersion step of setting a container having contained the powder P in a main body of a dispersion device, and dispersing the powder in the container by the main body of the dispersion device; and an ALD step for forming the coating film on a surface of the powder, by setting the container having been removed from the main body of the dispersion device in a main body of an ALD apparatus in such a state that gas can be introduced and be exhausted, introducing a gas for performing an ALD cycle into the container, filling the container with the gas, and then exhausting the gas.