A measurement device includes an air bag on a peripheral side, an air bag on a central side, and an air bag positioned therebetween. During blood pressure measurement, the air bags integrally behave, and the blood pressure is measured from the change in inner pressure thereof. During pulse wave measurement, the inner pressure of the air bag on the peripheral side is maintained to higher than or equal to the systolic blood pressure, and the measurement site is avascularized. The inner pressure of the air bag on the central side is maintained to the pressure near the blood pressure value, and the pulse wave is measured from the change in inner pressure thereof. The inner pressure of the air bag positioned therebetween is opened to atmospheric pressure, and the vibration of the air bag on the central side is prevented from propagating to the air bag on the peripheral side.
