A wet type developing apparatus in which liquid developer is fed onto a developing roller from a liquid developer supply roller immersed in the developing liquid within a liquid developer tank and an electrostatic latent image formed on a photoconductor drum and developed into a toner image by the developing roller is improved to enable the liquid developer to be fed an appropriate amount of feed from the liquid developer supply roller onto the developing roller without residual air in the surface region of the liquid developer supply roller, where a partition plate is disposed generally under the liquid developer supply roller within the liquid developer tank for partitioning the liquid developer tank in the rotational direction of the liquid developer supply roller, the partition plate having its upper end juxtaposed with a peripheral surface of the liquid developer supply roller over its total axial length across a gap spacing.