This article anaiyzes the Mapuche concept of Ngünechen, the creator and sustainer of the world by his/her own will and protector of the Mapuche family. I trace the evolution of the concept of Ngünechen from the 16th century and look at it's relationship with other spiritual beigns with which it has often been confused such as Ngen, Ngünenchen, Ngenechen, Ngenemapun, Elchen, Elmapun, Wenupülluam, Pülluam, Tren-Tren, Kai-kai, Wekufü, Mapurey, Genche and the Christian God. I draw on both ethnohistorical and anthropological data and propose three different ways to trace the origin and development of tihs concept each of which point to different aspects of this deity. 1) The hypothesis of the existence of an initial creator God that becomes less important as ancestral spirits prevail but that reappeas during the cosmic catastrophe brought on by the Spanish conquest, 2) Ngünechen as originating from the process of generalization of nature spirits, ancestral spirits and regional deities, 3) Ngünechen as taking the attributes of omnipotence and omniscience from the Christian God.