In this paper we propose "Boxed Economy Foundation Model"(BEFM), which is a model framework for agent-based economic/social models. It is the model framework which defines the set of concepts for modeling economy/society, and which supports to recognize, describe, and share the objects in the model, through the modeling process basically for social scientists. BEFM is an abstract of the real society from the viewpoint of economy, and consists of 12 major elements. Their class definitions and the relations between them are described. To execute the simulation based on BEFM, there is a platform called "Boxed Economy Simulation Platform" (BESP) to control the actual execution and manage the results. In addition, there are the tools called "Model Component Builder" and "Model Composer" to support implementation of the models.