A container refrigeration apparatus (10) includes a CA system (60) which controls the composition of the air in the container (11). The CA system (60) includes a gas supply device (30) which supplies nitrogen-enriched air, an intake duct (47a) which guides outside air to a first space (S21) on a suction side of an interior fan (26), and an exhaust duct (46a) which guides air in a second space (S22) on the blowout side of the interior fan (26) out of a container (11). The exhaust duct (46a) has an inlet at a location where the flow of the air blown from the interior fan (26) is blocked by a fan housing (27c).