A device though for guiding and controlling observations in spectroscopy with photographic plates used as detector is described. The equipment makes the star trail the slit, automatically turns the movement when the object runs away from the slit end and stops the trail when some final condition specified by the astronomer is reached. In addition, this guider performs some data acquisition related to the exposition: the real counts accumulated from the PMT, counts per seconds, the elapsed time and some other information used for controlling the exposure. First we described the main goals of this work and the operation principle, later we described the operation description from the user's point of view and finally a brief technical report is provided with two main points: hardware and software.