It is difficult to grasp the behavior situation of software, because a scale of software grows. In addition, it is hard work to understand the flow of complicated software such as OSs. Although the visualization of OS behavior has been developed, it is difficult to grasp the flow of internal processing of OS including interrupts and exceptions. In this paper, we describe the mechanism of the visualization of OS behavior including interrupts in Tender. In Tender, the information of the flow of internal processing of OS can be gathered by adopting the program structure, and the mechanism of visualization can be achieved at OS level by considering the processing type of interrupt and so on. Employing this mechanism, the information of the visualization of OS behavior can be used for studying OSs and for supporting program developments. We describe the mechanism of display and the visualization of the process scheduling as an example of OS behavior to study.