This article proposes and analyzes the use of the high-resolution Lhires III spectrograph as a pedagogical tool for teaching-learning concepts of optical spectroscopy. A methodology was developed and it was tested in a population of 20 students from different engineering programs at the Technological University of Pereira, Colombia. The methodology was implemented through a guide, which describes the 3 experiments that are part of the methodological proposal. Upon completion of the guide, students were asked to respond to a test. The Hake gain coefficient was used to measure the learning evolution of students and verify the methodology proposed in this study. 85% of the students affirmed they would like to explore in more depth the concepts of spectroscopy. Although more analysis may be required to verify the findings, these preliminary results show the experiments carried out with the Lhires III allow students to strengthen knowledge acquired in the classroom, fostering interest in science both at high school and university levels.