Machine-tool controller (1) having: a drive control unit (13) controlling, based on moving-body operational commands, feed-mechanism actuation to control moving-body move-to points; a modeling data storage (15) storing moving-body and structural-element modeling data; and a screen display processor (20) for generating, based on the moving-body move-to points, data modeling the moving body having been moved into a move-to point, and for generating, and displaying on a screen display device (47) screen, image data in accordance with the modeling data generated. The screen display processor (20) generates and displays the image data in such a manner that a display-directing point, serving as a referent for displaying the moving body and being defined to be on that portion of the moving body where there is a risk of interference with the structural element, coincides with the central portion of the screen display device (47) screen.