PURPOSE: To eliminate a switching time loss which is generated when switching a picture, by constituting the titled system so that a window magnifier use display plane moves together with a cursor point.

CONSTITUTION: A picture display plane and a window magnifier use display plane are provided in a graphic terminal. The picture display plane displays mainly a general drawing, and it does not move. The window magnifier use display plane can move, and displays an object so that it becomes N times larger than that of the picture display plane. The window magnifier use display plane always moves centering around a cursor point, and it is accompanied with one or plural planes in the upper and lower parts and the right and left, centering around the cursor point. The cursor point can move freely on the picture, but by following it, the window magnifier use display plane also moves.