The present invention relates to a method of controlling the microstructures of Cu—Cr-based contact materials for vacuum interrupters, in which a heat-resistant element is added to the Cu—Cr-based contact materials to obtain an excellent current interrupting characteristic and voltage withstanding capability, and contact materials manufactured thereby. The method of controlling the microstructures of Cu—Cr-based contact materials includes the steps of mixing a copper powder used as a matrix material, a chromium powder improving an electrical characteristic of the contact material and a heat-resistant element powder making the chromium particles in the matrix material fine to thereby obtain mixed powder, and subjecting the mixed powder to one treatment selected from sintering, infiltration and hot pressing to thereby obtain a sintered product.