a sphygmomanometer includes a base block and a cuff block having a cuff for restricting flow of blood , the cuff block being connected to the base block in such a manner that an angle of the cuff block with respect to a horizontal plane is variable within an angular range . the sphygmomanometer further includes a spring biasing unit for returning the cuff block to a position at a predetermined angle within the variable angular range of the cuff block when the cuff block is not used .