An automatic positive pressure breathing apparatus is provided, applicable to connect an upper respiratory tract of a user, which includes a gas generator, a gas flow sensing device, a humidification device, a heating device, a breathing tube, and a mask device. The gas generator includes a signal processing module and a filter. Wherein the signal processing module includes a control circuit and the filter is embedded in the gas generator. The first connecting end of the gas flow sensing device is positioned at one end of the gas flow sensing device and is connected to one side of the gas generator. The second connecting end is positioned at the other end of the gas flow sensing device. The gas flow sensing device includes a first pressure sensing element, a second pressure sensing element, and a radial structure.
