1. An imaging apparatus comprising: a spectroscopic part for separating a first luminous flux from a subject condensed by an optical system into a plurality of second luminous fluxes; a plurality of imaging sensors disposed corresponding to the plurality of second luminous fluxes; a generator for generating image data based on each of image signals generated by the plurality of imaging sensors; and a focus controller for executing a focusing operation of the optical system based on focus information generated by the plurality of imaging sensors, wherein each of the plurality of imaging sensors has a plurality of imaging pixels disposed on an imaging surface for capturing a subject image from the second luminous fluxes to generate image signals, and a plurality of focus detecting pixels disposed on the imaging surface in a specific pattern, for generating focus information about a focus state of the optical system with respect to the subject, wherein an arrangement of a first imaging sensor, which is one of the plurality of imaging sensors, with respect to the subject image is different from an arrangement of a second imaging sensor, which is another one of the plurality of imaging sensors, with respect to the subject image, in the specific pattern, a position of the focus detecting pixel of the first imaging sensor with respect to the subject image does not overlap with a position of the focus detecting pixel of the second imaging sensor with respect to the subject image.