[Object] In a configuration in which an image of a target is captured using a plurality of imaging elements, the plurality of imaging elements can be efficiently disposed in a limited space.[Solving Means] A branching optical system includes: a first branching optical system that separates first light belonging to a predetermined wavelength band from incident light in a first direction that is a surface direction of a plane including an optical axis corresponding to a normal direction of an incidence surface on which the incident light is incident； and a second branching optical system that is provided subsequent to the first branching optical system and separates, from second light after the first light is separated from the incident light, third light that is a part of the second light, in a second direction crossing the plane.
