Provided is an artificial nose and a breathing circuit provided with the artificial nose, including: an outer shell； a moisture permeable and water resistant film 6 disposed on an entire circumference of an internal surface of the outer shell, forming a water retention region with the outer shell, and forming an aeration region on an internal surface side thereof； a feed water inlet provided in the outer shell to supply water to the water retention region； a heat and moisture exchanger element loaded in the aeration region； and a heater disposed outside the outer shell, wherein the water supplied from the feed water inlet is retained in the water retention region by the moisture permeable and water resistant film, an inspiratory gas and an expiratory gas pass through the heat and moisture exchanger element loaded in the aeration region, and the artificial nose carries out a first heating and humidifying process of the inspiratory gas in which heat and moisture included in the expiratory gas passing therethrough are captured and retained by the heat and moisture exchanger element and the heat and the moisture are discharged to an inspiratory gas passing therethrough next, and a second heating and humidifying process in which only water vapor generated by heating of the heater passes through the moisture permeable and water resistant film and is supplied to the inspiratory gas passing through the heat and moisture exchanger element to heat and humidify the inspiratory gas and also the inspiratory gas in the heat and moisture exchanger element is heated by the heater.
