EN
This paper presents Thomas Aquinas’ concept of creation as a metaphysical theory of the origin of being. The concept of creation was investigated mostly as a theological problem but in Aquinas’ thought (also when it is used in the theological context of his works) it is understood as a metaphysical explanation of existence and plurality of contingent beings. Creation is a way of explanation how the First Cause acts and how this action results in the existence of numerous accidental beings. Creation is not a natural transformation or a production of something on the basis of the previous elements. It is a “production” in being (productio in esse) with no previous conditions (creatio ex nihilo). The formal end of the creative action is the act of existence (ipsum esse) of accidental beings. The creation of accidental beings generates mutual relations of the Creator and the cre-ated beings.