Abstract: Provided is a lateral flow assay device capable of detecting a traumatic brain injury marker including a sample pad into which a blood sample containing a traumatic brain injury marker is injected, an adsorption pad including a probe which is mixed to the marker when the traumatic brain injury marker moves from the sample pad to form a traumatic brain injury marker complex, and a porous film which fluid-communicates with the adsorption pad and capillary-migrates the traumatic brain injury marker complex from the adsorption pad to a detection line, in which the probe includes a capture antibody consisting of an antibody labeled with a specific binding material specifically binding to the traumatic brain injury marker and a detector antibody consisting of an antibody labeled with a fluorescent material having a relatively long emission lifetime of 1 microsecond or more, and a mixture of at least two different kinds-origin antibodies is used as the antibody labeled with the specific binding material or the fluor