A method for manufacturing an alumina sintered body of the present invention comprises: (a) forming a mixed powder containing at least Al2O3 and MgF2 or a mixed powder containing Al2O3, MgF2, and MgO into a compact having a predetermined shape; and (b) performing hot-press sintering of the compact in a vacuum atmosphere or a non-oxidizing atmosphere to form an alumina sintered body, in which when a amount of MgF2 to 100 parts by weight of Al2O3 is represented by X (parts by weight), and a hot-press sintering temperature is represented by Y (° C.), the hot-press sintering temperature is set to satisfy the following equations (1) to (4) 1,120≦Y≦1,300  (1) 0.15≦X≦1.89  (2) Y≦−78.7X+1,349  (3) Y≧−200X+1,212  (4).