This study aims to clarify the firm in neo-institutional context. The firm is a particularly dynamic, constantly evolving process and an organizational structure. The firm is a symbiosis of entities, internal and external regulations, market and non-market mechanisms and relations, legal and economic conditions and effects. In the legal aspect, it is the sum of relationships developing inside and outside the scope of the organization legal process through which the property is managed. Economically, it is an organization created to profit from the production optimum. In the neo-institutional context, it is an abstract mechanism to control processes -on the one hand legal, economic, social and other administrative, marketing and arbitration -Contract processes. These companies have resources to create a balance between the costs behavioral resources for speed and security. The assessment of such corporate efficiency is based on transaction costs.