The method of manufacturing a solid state imaging device of the invention comprises a step of adding carboxylate as a dyeing assistant auxiliary to the aqueous dyestuff solution when forming dyeing layers of acrylic-based resin on a semiconductor substrate on which a solid state imaging element is formed. Therefore this invention provides a solid state imaging device with a color filter which is dyed densely, is flat, thin, and excellent in spectral characteristics. A transparent planarization resin layer (the material is e.g. acrylic) is formed on a semiconductor substrate, and a shading layer and a planarization resin layer are successively formed thereon. A synthetic resin is prepared and added photosensitizer of diazo compound. On the above-mentioned planarization resin layer, the layer of the synthetic resin is coated to be 0.2 to 0.8 .mu.m thick, for example, by a spin coat method. Then the synthetic resin is selectively exposed with a stepper, and developed to form patterns of a color filter. Then, the resin with the pattern is dyed to be a cyan layer. In the step, ammonium acetate and a urea compound are added to the aqueous dyestuff solution.