A measurement device for measuring an airflow volume and a ventilation resistance, comprising: a casing that includes a first air duct with an air inlet, the air inlet being configured to take in air; a straightening grid provided in the first air duct, the straightening grid being configured to straighten the air taken from the air inlet; a first chamber provided in the first air duct, in which air that has passed through the straightening grid is taken; an opening plate provided in the first air duct, the opening plate including an opening (16a, 16b) allowing the air taken in the first chamber to pass therethrough; a second chamber provided in the first air duct, in which air that has passed through the opening (16a, 16b) of the opening plate is taken; pressure sensors (5a, 5b) provided to the first air duct, the pressure sensors (5a, 5b) being configured to measure a first pressure, a second pressure, and a third pressure, the first pressure being air pressure from the air inlet to the straightening grid, the second pressure being air pressure in the first chamber, the third pressure being air pressure in the second chamber; a specific opening disposed in a part of the first air duct, the specific opening being configured to allow the opening plate to be replaceable; an open/close portion configured to open and close the specific opening; and a duct forming a second air duct between the measurement device and a measurement target being a wind blowing apparatus to be measured, wherein the duct includes an air duct wall member that forms an air duct wall of the second air duct, and the air duct wall member is formed of a foldable material, wherein the duct includes sleeves and support rods, wherein the support rods are mounted to the duct detachably to hold the shape of the duct, wherein the sleeves are disposed on the air duct wall member, and the sleeves are configured to pass the support rods through it. a casing that includes a first air duct with an air inlet, the air inlet being configured to take in air; a straightening grid provided in the first air duct, the straightening grid being configured to straighten the air taken from the air inlet; a first chamber provided in the first air duct, in which air that has passed through the straightening grid is taken; an opening plate provided in the first air duct, the opening plate including an opening (16a, 16b) allowing the air taken in the first chamber to pass therethrough; a second chamber provided in the first air duct, in which air that has passed through the opening (16a, 16b) of the opening plate is taken; pressure sensors (5a, 5b) provided to the first air duct, the pressure sensors (5a, 5b) being configured to measure a first pressure, a second pressure, and a third pressure, the first pressure being air pressure from the air inlet to the straightening grid, the second pressure being air pressure in the first chamber, the third pressure being air pressure in the second chamber; a specific opening disposed in a part of the first air duct, the specific opening being configured to allow the opening plate to be replaceable; an open/close portion configured to open and close the specific opening; and a duct forming a second air duct between the measurement device and a measurement target being a wind blowing apparatus to be measured, wherein the duct includes an air duct wall member that forms an air duct wall of the second air duct, and the air duct wall member is formed of a foldable material, wherein the duct includes sleeves and support rods, wherein the support rods are mounted to the duct detachably to hold the shape of the duct, wherein the sleeves are disposed on the air duct wall member, and the sleeves are configured to pass the support rods through it.