Economics is the study of the problem of managing rare resources as efficiently as possible. The allocation of resources is determined by the interactions between consumers and firms. It is essential to analyze the results of various economic activities in order to understand consumer behaviors and firm strategies. Therefore, by modeling behaviors of consumers and firms, it is necessary to learn about supply and demand of goods. Economic trading exists when there is a balance between demand and supply of goods, which can be understood by the concept of market equilibrium. Further, based on the concept of social welfare, the study discusses the policies to achieve the desirable resource allocation. Microeconomics provides a theoretical framework for such economic analyses. This course aims to understand how the concepts of microeconomics solve the existing economic issue. Although mathematics is used in this course, the main aim is for intuitive understanding through the use of diagrams. Knowledge of microeconomics opens up new perspectives in other fields such as business administration, politics, and sociology.