A solid image pickup element is adhesively attached via a spacer to the light leaving end of a color separation prism which is employed in a television camera to separate the light of an object from an optical lens system into a plurality of wavelength band components. The spacer has at least one surface to be engaged with either the color separation prism or the solid image pickup element, and the engagement surface is inclined relative to the light leaving optical axis of the prism. Therefore, a single spacer can be satisfactorily utilized for different clearances between the prism and the solid image pickup element.