A scanning device generally referred to as a "laser scanner", used to obtain 3D data of objects by irradiating laser beams, is used in the field of cultural properties, and is starting to achieve significant results. The technique to record complex 3D data with high accuracy and speed, without touching or destructing an object, makes it an essential tool in the field of cultural properties, as well as arousing interest in the displaying of such data on a computer, and in the various possible usage of the obtained 3D images. The authors have implemented this laser scanning technique to obtain data for such various fields as architecture, fine arts, monuments, and historic sites, with good results. This paper is written to consider application of this technique for efficient conservation of cultural properties, referring to the 3D laser scanning activities performed by authors up to the present. The 3D digital archive making with laser scanner requires two steps, which are actual measurement works and digital processing of the data acquired. The acquired point clouds in three dimensions can be displayed on a computer by using the exclusive software and we have to process (align, merge and so on) these data considering subsequent works also. Up to the present, the authors have performed many practical applications using 3D digital archives of cultural properties measured by laser scanner. These are valuable records for various purposes: handing over to future generations, creating 2D information, investigating inclinations, preparing basic data for examination of a restoration plan, visualizing CG animations and others. In this paper, the authors wish to introduce the method of measurement using laser scanner, and the subsequent processing of the obtained data, in order to clarify the validity and possibility of application for creating efficient and valuable digital archives.