Abstract: We consider Bernstein inequality for the Riesz derivative of order of entire function of exponential type in the uniform norm on the real line. The interpolation formula is obtained for this operator; this formula has non-equidistant nodes. By means of this formula, the exact Bernstein inequality is found for all, namely, the extremal entire function and the sharp constant are written out. © Pleiades Publishing, Ltd. 2023. ISSN 1064-5624, Doklady Mathematics, 2023, Vol. 108, No. 3, pp. 524–527. Pleiades Publishing, Ltd., 2023. Russian Text The Author(s), 2023, published in Doklady Rossiiskoi Akademii Nauk. Matematika, Informatika, Protsessy Upravleniya, 2023, Vol. 514, pp. 118–122.