An industry is the initiator of every economy's development. Industrial consumer behaviour is the process that changes and it is necessary to observe it with the aim of creating better cooperation and business. It is difficult to understand this process due to the consumers’ uniqueness. However, it is easy to have an impact on consumers, either through TV-s, radios, or Internet. It is important that the message sent to consumers is coordinated with the standards. The customer has the freedom of choice. One of the most important conditions of seller’s success is the understanding of industrial customer’s business process. To continue, the consumer’s behaviour should be observed with the aim of adjustment to the customers and creating long-term relationships. Gas supply stands for the selling and reselling the gas to the customer. There are two categories of natural gas customers in Republic of Croatia; these are households and industrial consumers. The customers from the first category buy the natural gas by regulated price that is determined by the Government of Republic of Croatia and competent regulatory agency. The second category includes industrial consumers, precisely customers that freely negotiate the price with the supplier. The large industrial consumers depend on the price of the gas and try to prevent the risk of price change with long-term contracts. Finally, the industrial customers are very important for the segment of economy and it is advisable to observe their requirements in order to create mutually useful cooperation.