The objective of this research is to evaluate the relationships of the network formed by the important milk cluster in the city of Umuarama, State of Parana (PR)/BRAZIL, using the Social Network Analysis (SNA) focusing on the collective gains and competitive advantages of this cluster. The methodology used was qualitative and quantitative. Questionnaires were applied to the network for the characterization of the existing relationships between them, and also to present the analysis of network measures using the UCINET software and the graphics schemes of networks. It was found that this milk production network appears to be diffuse, and that there are few solid relationships, which have no central coordination; the network did not present governance relationships nor a defined empowerment with significant transaction costs relationships. The relevance of this paper is to present a procedure of study in networks that can be reproduced in future researches.