An image forming method is disclosed. The method comprises steps of supplying developer (50) onto the surface of a developing roller (141) having a high magnetic field not less than 1000 G at the surface thereof, and making color superposed images on an image carrier (1) by repeating twice or more the step of non-contact-developing a latent image formed on the image carrier through an oscillating electric field formed between the developing roller and the image carrier. A carrier in the developer has a volume average particle size of not more than 50 µm and the saturation magnetization amount σ S of the carrier particles is not more than 50 emu/g. A toner having narrow particle size distribution is preferably used.