An imaging apparatus mounted in a vehicle includes an imager substrate, a housing, and a heat dissipator. The imager substrate has an image sensor mounted thereon. The housing is equipped with a rear wall extending in an in-plane direction perpendicular to a thickness of the imager substrate and has the imager substrate disposed therein. The heat dissipator is arranged between the imager substrate and the rear wall in contact therewith to transfer heat from the imager substrate to the rear wall. The rear wall has a substrate-facing surface facing the imager substrate through the heat dissipator and also has a retainer arranged on the substrate-facing surface to hold the heat dissipator thereon. This structure ensures enhanced stability in releasing thermal energy from the image sensor or the imager substrate.