A fine positioning device is formed of a rigid support member; a first set of radial flexible-beam displacement mechanisms provided symmetrically to each other on the support member to produce angular displacements about a first axis; a second set of radial flexible-beam displacement mechanisms provided symmetrically to each other on the support member to produce angular displacements about a second axis which is perpendicular to the first axis; a third set of radial flexible-beam displacement mechanisms connected to either one of the sets of radial flexible-beam displacement mechanisms to produce angular diaplacements about a third axis which is perpendicular to both the first and second axes; and a fine motion table fixed on the radial flexible-beam displacement mechanisms which are other than those connected to the radial flexible-beam displacement mechanisms for producing angular displacements about the third axis.