A breathing filter comprises a base, a set of filter elements arranged on the base and a hollow shell.The base comprises a hollow pipe body, a plate body extending outwards from the peripheral edge of the top of the library body, and two support frames respectively arranged on two opposite sides of the plate body and extending upward from the top of the plate body.Two first-class ports are respectively formed at both ends of the pipe body.The filter element is opened by the support frame, and the filter element cooperates with the support frame and the plate body to define a first filter chamber connected with the pipe body to support the first-class port.The shell includes a shell arranged on the filter element, which cooperates with the filter element to define a second filter chamber, and the shell forms a second flow port to connect the second filter chamber.一種呼吸過濾器，包含一基座、一套設於該基座的過濾元件，以及一呈中空狀的外殼。該基座包括一中空的管體、一自該館體頂部的周緣向外延伸的板體，以及兩分別設置於該板體的兩相反側並且自該板體頂部向上延伸的支撐架。該管體的兩端分別形成有兩個第一流通口。該過濾元件被該等支撐架撐開，該過濾元件與該等支撐架以及該板體三者共同配合而界定出一連通管體支該等第一流通口的第一過濾室。該外殼包括一套設於該過濾元件的殼體，該殼體與該過濾元件兩者共同配合而界定出一第二過濾室，且該殼體形成有一連通該第二過濾室的第二流通口。
