To provide a method and an apparatus for visualizing the appearance of the deformation in the inner part of a formed article to clarify the checking of working processing and the cause of defect in the formed article, in the working of a complicated form parts applying the three-dimensional plastic-deformation.

A model material resembled with the deforming characteristic of a metallic material embedding a gage mark in the inner part of the material is filled up into a model die and pressurized with a tool by the prescribed working ratio and at the same time, the gage mark is picked up by applying radiation from a single focus with a TV camera for radiation. Successively, for forming a parallax, the model die is parallel shifted in the horizontal direction to the parallel with the picked up surface of the TV camera for radiation, and the gage mark is picked up by applying the radiation from the single focus with a TV camera for radiation. After repeating these operations up to the completion of the pressurization, two-dimensional coordinate of the gage mark is calculated from the picked up image and the three-dimensional coordinate is calculated from the two-dimensional coordinate forming the gage mark, and the three-dimensional data of the gage mark and the shape data of the model die are superposed and indicated.