The fundamental characteristics of analytical stereoplotters compared to the analog stereoplotters is their facility to use them and the versatility given by the on-line of a mini-computer. Analog stereoplotters, even those classified universal, are generally designed at the beginning for cartographic plotting from aerial photographies. Few of them have the capability to be used in non cartographic field such as biostereometrics applications. Analytical stereoplotters are usable in all kind of restitution, monoculary or stereoscopically. The main particularity of TRASTER, the analytical stereoplotter built by Matra, is its stereo viewing system obtained by an optical projection in polarized light of the photographies in place of the conventionnal binocular system. This feature increases the operator comfort, gives a better facility of the stereophoto-grammetry adaptation to not confirmed operators and allows the stereo view by several people in the same time. Thanks to the incorporated computer, specific softwares can be easily adapted to Traster. Restitution of stereopairs are possible in on-line mode on the drafting table. Three dimensional coordinates of objects to be plotted can be stored in numerical form for further processing.