To provide a sphygmomanometer cuff capable of performing a precise bloodless blood pressure measurement by reducing or eliminating a fluctuation in the cuff pressure due to a temperature fluctuation in the pressure rising (pressurization) by a vasopressor bloodless sphygmomanometer, a step-down decompression or a linear decompression (a fixed speed decompression to a time) by a decompression type bloodless sphygmomanometer by constituting the inside of an air bladder of a substance with a high heat capacity per unit volume to suppress the unnecessary temperature and pressure fluctuations inside the air bladder in the air bladder provided in the sphygmomanometer cuff for bloodlessly measuring the blood pressure.

This sphygmomanometer cuff 10 is provided with the air bladder 12 worn on the body surface of a subject, injecting air therein and compressing the artery, detects pulsation components obtained synchronizedly with the heartbeat and bloodlessly measures the blood pressure. The inside of the air bladder 12 is constituted of the substance with high heat capacity per unit volume.