Objective: The purpose of this study is to suggest the hierarchical structure with three layers of input task, input interaction, and input device. Background: Understanding the input interaction is very helpful to design an interface design. Method: We made a model of three layered input structure based on empirical approach and applied to a gesture interaction in TV. Result: We categorized the input tasks into six elementary tasks which are select, position, orient, text, and quantify. The five interactions described in this paper could accomplish the full range of input interaction, although the criteria for classification were not consistent. We analyzed the Microsoft kinect with this structure. Conclusion: The input interactions of command, 4 way, cursor, touch, and intelligence are basic interaction structure to understanding input system. Application: It is expected the model can be used to design a new input interaction and user interface.