To provide an interior illumination screen that can obtain a fantastic lighting effect with soft light of various colors and manufacture with ease and at low costs.

A frame 3 has a plurality of cells 9 separated by partitions 6. Screen 1, 1a and 1b are formed by providing a diffusion translucent substance 4 on one side in length direction of the frame 3. The translucent substance 4 mixes approximately uniformly light of respective color that is incident into the respective cells 9 out of a chromatic color light source 2 arranged in the opposite side of the translucent substance 4. The translucent substance 4 reflects about uniform color at every cell on the opposite side of the light source 2 of the screen 1, 1a and 1b.