PURPOSE: To know the change of a superimposed part clearly at a glance and to give suitable advice to a golfer by a coach by diagnosing a swing form according to the change of a superimposed picture and a moving image when the swing form of the golfer is displayed as the moving image from a still picture displayed in a display means.

CONSTITUTION: A display 77 is provided to project the picture, for which the swing of a golfer 1 is recorded, or to display the two-dimensional stick picture or three-dimensional wire frame model picture of the swing form for the golfer 1 and a color printer 78 prints those pictures with being colored. A mouse 79 is provided to designate coordinates for the body of the golfer 1 or the measuring points of a club 22 or a ball 10. Thus, the swing form of the golfer 1 is photographed in a front direction from right and left sides and only by inputting the measuring points for the respective pictures of the photographed golfer 1, club 22 and ball 10, an evaluation parameter is prepared. Then, the evaluation parameter is compared with the evaluation parameter of a professional golfer and a swing error is detected. Afterwards, the suitable advice to the error is applied to the golfer 1.