Disclosed are a method and an apparatus for affixing a bearing box, wherein, in order to affix high-pressure or low-pressure steam turbine casings (LP1, LP2, HP) in storage spaces (S1 to S3) provided in a concrete mount (12) so that the steam turbine casings do not move in a direction (arrow ''a'' direction) perpendicular to the direction of a rotor shaft, a cubic block (16) from which transverse anchors (20a, 20b) are upward projected, is provided, and concrete is casted into a concrete introduction space of the cubic block (16), to affix the cubic block (16) in the concrete mount (12).