Spirulina is a primitive micro algae appeared on earth 3.5 billion years ago. Being able to photosynthesize, by absorbing twice its biomass CO2 and by using atmospheric nitrogen, has contributed to the shaping of oυr modern atmosphere, incorporating precious oxygen. Biologically it is characterized as a thermophilic organism (optimum 35C) and an alkalophilic one (PH 9-11). These unique environmental conditions are secured in the Geothermal Field of Nigrita, (Therma), Greece, using the thermal mineral waters of the region, rich in pure CO2. The high photon flux of the area (300 sunshine days/year), contributes to a high photosynthetic activity, resulting in the production of high quality spirulina. Historically, in the sixteenth century, when the Spanish invaders conquered Mexico, they observed the Aztecs to collect with fine nets from the lake Texcoco, natural spirulina, making a local cake from it, a major part of their diet. Today, this procedure is practiced systematically in Texcoco lake. A similar practice is followed in the lake Kossoron in Chad, Africa, where spirulina is a main dietary component of local populations, especially in pregnant women and in the local medicine practices. After the 2nd World War, German and French professors studied spirulina in details. In 1967, spirulina was <> by the International Association of Micro-biologists, as the best nutritional source for the future. More recently, NASA chose spirulina as the main dietary source for astronauts. The United Nations, through CISRI-ISP, encourages their members to use spirulina to achieve sustainable development. Spirulina is unique for both vegetarians and non-vegetarians.