This article examines the nature of legitimate expectations in international investment law. The author considers international investment case law to suggest that legitimate expectations consist of four basic elements: specific representation or promise made by the host State, legitimacy, reasonability, and objectivity of expectations, reliance (trust) the investor had in the representation made by the host State and the substantive benefit received by the investor by way of representation or promise made by the host State. After briefly explaining the basics of the protection of legitimate expectations, the article addresses each element, including the criteria of effective representations or promise made by the host State that is capable of creating legitimate expectations. It also shows that the focus should be placed on the reliance element.