To provide a manufacturing method of color filter and a manufacturing method of solid-state imaging device, capable of reducing color mixing of pigments in a color filter by enhancing the cured state of the color filter.

In the manufacturing method of color filter, a colored photosensitive resin 31a is formed on a substrate 1 to be treated, a pattern of the color filter 31 is formed by exposing and developing the colored photosensitive resin 31a; and thereafter, the color filter 31 is heat-treated in an atmosphere, in which the oxygen concentration is suppressed to be 5% or lower, and the color filter 31 is made to harden.