Poly (3-hydroxybutyrate), PHB, is a biocompatible and biodegradable polymer accumulated in microorganism cells as a reserve material. PHB production in biotechnology laboratories has been carried out by using expensive instruments such as autoclave, a large thermostatted shaker, a freeze dryer, and an automatic refrigerated centrifuge. A very simple method of PHB production with Alcaligenes eutrophus for use in science teaching freshman laboratory is reported in this article. The study was conducted with 6 prospective elementary teachers. An ordinary glass 1 L jar, a 4L pressure cooker and thermostate for aquariums were used in fermentation process of the bacterium in nutrient solution containing table sugar as a substrate. In conclusion, the thermal and characterization data confirmed the PHB structure. Science Process Skills are investigated in this study. Qaulitative method was used to acquire data and analyze the science process skills experienced by the students in the experiment. The article discusses on development of some science process skills during the experimental process and gives suggestions for future use and research.