Industrial Revolution 4.0 brought changes and developments in consumer behavior today. The emergance of disruptive innovation such as digital economics, artificial intelligence, big data, robotics and so on. As disruption happened, telecommunication industry is the main key. Competition in the telecommunications industry becomes strict, encouraging smartphone product to continue to grow to compete in market share. Apple.inc, one of the giant companies from Cupertino, California, is in the spotlight. Apple's smartphone, namely iPhone can survive and becomes a company that has a good brand image for consumers, especially millennials or Y generation, who currently dominate the market. This study aims to determine millennial loyalty in using iPhone products. By using qualitative research methods and triangulation techniques, this study describes in detail the problem phenomena that currently occur. In this study, millennials use iPhones because following the trends, to be appreciated by its environment, one of the examples by utilizing social media and being loyal because of the security and the convenience. Millennials are also willing to save in order to buy something based on wants and needs. However, a limitation and barrier for millennials in being loyal to the iPhone is the price. This research is expected to provide information for companies related to consumer behavior in the era of the industrial revolution 4.0.