In this work, AATOM, a microscopic agent-based model that simulates movement and operations in the airport terminal is presented. Specifcally, the model includes the main handling processes required for outbound passengers namely, check-in, security and border control. Furthermore, basic facilities for discretionary activities are modelled namely, bathrooms, restaurants and shops. The model has an accompanying architecture, the AATOM architecture that is described in this work as well. The objective of the model is to serve as a basis for several studies in the area of airport terminal operations. It will be used to investigate properties in the fields of security, efficiency, resilience and possibly other fields like safety, and it will be used to investigate the relationship between any of these areas.@en