A ducted fan includes a fan that generates an airflow that flows substantially parallel with the axis of the rotating shaft of the fan; a duct, arranged around the fan, that extends in the direction of the rotating shaft of the fan and includes an airflow inlet defined by the upstream end and an airflow outlet defined by the downstream end, and that has a ramp portion formed in the inner face of the airflow inlet; an airflow guide portion, provided at the airflow outlet, that introduces air from outside of the duct to a position downstream of the airflow outlet; and a negative-pressure forming portion, provided at the downstream end of the airflow guide portion. The negative-pressure forming portion generates a negative pressure near the downstream end of the airflow guide portion when air passes by the negative-pressure forming portion.