There is provided a roll machining apparatus for machining the surface of a roll, which can accurately support a roll by hydrostatic bearings while absorbing thermal expansion of the roll in the length direction, thus enhancing the machining precision. The roll machining apparatus can include a first hydrostatic radial bearing for receiving the radial load of a first spindle and rotatably supporting the first spindle, a hydrostatic thrust bearing for receiving the thrust load of the first spindle and limiting axial movement of the first spindle, a second hydrostatic radial bearing for receiving the radial load of a second spindle and rotatably supporting the second spindle, and a floating thrust having a thrust bearing for receiving the thrust load of the second spindle. The floating thrust selectively limits and permits axial movement of the thrust bearing.