PURPOSE: To easily judge the result of boring by equipping first and second image memories, and storing the image data of the mark given to a work and the image data of a bored hole, and composing each stored image data prior to output.

CONSTITUTION: An image processing circuit 56 is connected to an X-ray camera 2 through an image input circuit 55, and a central processing circuit 60 is connected capably of data exchange to the image processing circuit 56 through an output means 61. The transmitted image of a mark by the X-ray application means 6 connected to this central processing circuit 60 is picked up with an X-ray camera 2, and it is processed into an image processing circuit 56, and the image data are inputted into the central processing circuit 60. It is positioned to a specified place so as to bore a hole by driving an XY table mechanism 22 and a boring means 3, and also it is stored in a first image memory 57. Moreover, the image after boring is stored in the second image memory 58, and both image data of the mark and the hole are composed and outputted to display the positional relation between the mark and the hole.