The present invention discloses a built-in nasal filtering device that includes a body, an airbag bag, and a filter. The frame body comprises a frame portion corresponding to the position of the nostrils, and the frame portion defines a telescopic direction, and the air bag is connected to the frame portion, and the air bag can be adjusted from a collapsed state to an unfolded state in the telescopic direction, and the airbag bag is permeable. When in the unfolded state, an opening and an accommodating space are formed, and the filter member is positioned relative to the frame portion. Through the above design, the creation can adapt to users with different sizes of intranasal space.本創作公開一種內置式鼻用過濾裝置，其包括一架體、一透氣囊袋以及一過濾件。架體包括一對應鼻孔位置的框部，且框部界定有一伸縮方向，透氣囊袋連接於框部，透氣囊袋能沿伸縮方向從一收合狀態調整至一展開狀態，且當透氣囊袋處於展開狀態時形成有相互連通的一開口與一容置空間，過濾件的位置相對於框部。通過上述設計，本創作能適應鼻內空間大小不同的使用者。
