We show a novel way to achieve superdirectivity of optically small nanoantenna. These antennas are an optically small spherical dielectric nanoparticle with a notch in which a point source is located. We explain the effect of superdirectivity by the resonant excitation of high-order multipole modes which are usually negligible for optically small dielectric nanoparticles but become resonant due to the notch. For such an antenna we have revealed a beam steering effect at nanoscale – strongly subwavelength sensitivity of the beam direction to the position of the source phase center. We have confirmed both predicted superdirectivity and beam steering effect experimentally through scaling to microwave frequency range.