Provided is a respiratory assistance device (1), which is used by a patient with a respiratory impairment, sending out air which is inhaled into the patient's respiratory tract. Specifically, the respiratory assistance device (1) comprises: a ventilator (11) which gathers and sends out air into a patient's respiratory tract; an upstream-side humidifier (10) which humidifies the air which is gathered by the ventilator (11) on the upstream side of the ventilator (11); and a downstream-side humidifier (12) which humidifies the air which is sent out from the ventilator (11) on the downstream side of the ventilator (11). Thus, sufficient humidification of inhaled air is carried out even if the inhalation path from the ventilator is short.