Abstract: The present invention discloses a unit for validating an in situ decontamination effect, including a connecting end. A left end of the connecting end is in communication with any space that needs gas decontamination. A right end of the connecting end is connected to a closed isolation damper. A right end of the closed isolation damper is connected to a hollow decontamination validation chamber. A sealing cover is sleeved over an outer wall of the decontamination validation chamber. A mesh cup is placed inside the decontamination validation chamber, and the mesh cup is used for placing a bioindicator. In addition, the present invention further discloses a device for filtering biologically contaminated air, including a unit for validating an in situ decontamination effect and a hollow box installed with a high efficiency particulate air (HEPA) filter. The unit for validating an in situ decontamination effect is in communication with the hollow box.