BIOSENSOR

Disclosed herein is a biosensor. The biosensor includes a measuring layer configured to measure whether reaction to a biological sample has occurred. A lower cover is disposed below the measuring layer, and is provided with a lower protrusion which protrudes between an open window configured to allow a measurement area of the measuring layer to be exposed and an upper protrusion of an upper cover so that the lower protrusion is spaced apart from the upper protrusion by a predetermined gap and which presses the measuring layer so that a top of the measuring layer upwardly protrudes from the open window. The upper cover is disposed on a top of the measuring layer, and is provided with the open window and the upper protrusion configured to protrude from an outer portion of the open window in a direction in which the upper protrusion is coupled to the lower cover. Accordingly, the biosensor can minimize the difference in the amount of blood serum reaching a final reaction layer while minimizing the amount of biological sample required for measurement.