Abstract: A test strip includes a substrate, a spacer layer having a notch, a reagent layer, a support layer, and a cover layer having a covering portion covering the notch and a channel portion extending rearward from the covering portion corresponding to a rear end of the notch. The substrate is attached under the spacer layer and has a reaction region exposed from the notch. The support layer is located at two sides of the notch and connected to the cover layer and the spacer layer to make the channel portion away from the spacer layer at a vertical distance. The support layer, the covering portion, the notch, and the substrate form a reaction chamber for allowing an analyte solution to react with the reagent layer coated on the reaction region, and the support layer, the channel portion, and the spacer layer forms a channel for exhausting air.