An up/down movable diaphragm is disposed to an upper surface portion of a stirring vessel so as to airtightly cover the upper surface portion, a drive shaft passing through the diaphragm is fixed and vertically disposed to the diaphragm, and a stirring blade coupled with and fixed to a lower end portion of the drive shaft so as to be orthogonal thereto is composed of a laterally long and oval sheet-shaped member having a major axis and a minor axis passing through a center thereof, and a stirring is performed by moving the stirring blade up and down. With this arrangement, there are provided a stirring blade and a stirring apparatus which do not apply a strong shearing force to a stirring liquid, do not have an anxiety of polluting the stirring liquid, and can sufficiently fluidize, mix, disperse, and homogenize the stirring liquid in a stirring blade and a stirring apparatus for performing a stirring in fields of medicine and food.