A cuff includes a cuff main body portion and a gripping portion provided on an outer peripheral surface of the cuff main body portion. The cuff main body portion includes an air bladder, a tightening belt wrapped around an outer side of the air bladder, and a wrapping length adjustment mechanism for variably adjusting a wrapping length of the tightening belt. The wrapping length adjustment mechanism has a bias spring for pulling and biasing the tightening belt in a direction in which the wrapping length of the tightening belt is shortened, a first restriction portion for restricting extension of the wrapping length, and a second restriction portion for restricting shortening of the wrapping length. The gripping portion includes a push button for switching actions of the two restriction portions. In this configuration, the cuff may be easily attached to a measurement site regardless of the circumferential length of the site.