A holographic-based directional sound device is provided, the device including: a sound wave generating means generating a sound wave; and a flat plate configured to have the sound wave generating means installed at the center so as to radiate the sound wave to the outside through a surface, and to be composed of a plurality of unit cells, in which at least one groove is formed on a surface of the unit cell, and a radiation angle of the sound wave is determined according to a depth of the groove with respect to the unit cell, wherein the depth of the groove is determined by an individual surface admittance calculated by a cosine function or a sine function of the sum of a first value and a second value on the basis of a preset radiation angle of the sound wave and a preset frequency of the sound wave.