An imaging apparatus capable of outputting video signals in a plurality of formats is disclosed. The imaging apparatus includes: color separating optical system for separating incident image light into light beams of primary colors; first, second and third imaging portions respectively including a first, second and third set of pixels arranged at regular pitches in a first direction and in a second direction which is perpendicular to the first direction, the first, second and third imaging portion receiving each one of the light beams of primary colors separated by the color separating optical system and respectively accumulating them in the first, second and third set of pixels, as an image signal, the first set of pixels being shifted by 1/2 pitch with respect to the second and third set of pixels in the first direction and the second direction; an A/D convertor for converting the image signals of primary colors accumulated in the first, second, and third sets of pixels into digital signals; an interpolation processor for performing interpolation processing to the image signals of the primary colors which are converted into the digital signals in the A/D convertor, thereby doubling the number of pixels in the first direction and doubling the number of pixels in the second direction; and a pixel-number convertor for performing format converting processing for converting the image signals of primary colors which are interpolated in the interpolation processor into image signals based on any one of the plurality of formats.