To fit widow glass of various shapes into the window frames of vehicle bodies with reliability.

An automatic vehicular-window glass fitting device 1 comprises a robot arm 5, a gripper 6, a CCD camera 7, an image processor means 8 and a robot-arm controller 9. The robot arm 5 has the gripper 6 and the CCD camera 7 at its tip. The image processor means 8 has a window-frame image processing part, a window glass image processing part and an image comparing part. The window-frame image processing part produces window-frame image maps, while the window glass image processing part generates window glass image maps. The image comparing part detects the positional dislocation of the center of gravity and the angular dislocation about the center of gravity between a window-frame image and a window glass image. The robot-arm controller 9 has an operation controlling part and an operation correcting part. The operation controlling part controls the operation of the robot arm 5, while the operation correcting part corrects the operation of the robot arm 5.