A glass stress test method includes breaking a glass, analyzing a shape of a crack of a broken portion of the glass in a plan view, finding a breakage origin of the glass based on the shape of the crack in the plan view, analyzing a cross-section of the breakage origin, and calculating a stress of the glass based on a cross-sectional analysis result of the breakage origin. The stress of the glass is calculated as a value proportional to a floor constant defined by a condition of a floor surface disposed when the glass is broken.