In examining the way school health teachers (yogo kyoyu) and students in trouble define and manage students' troubles at junior-high school infirmaries (hokenshitsu), We identify special aspects of social interaction critical to that process. Using 'school health teacher's stock of knowledge at hand to the student-in-trouble' and 'filling-in-the-form-of-using-infirmary' activity practically, good work is organized in and through the formal structure of the school health teacher and student-in-trouble interaction, and then the student's trouble is socially understood and managed. That is to say, 'school health teacher's stock of knowledge at hand to the student-in-trouble' is constructed naturally in and as of the school health teacher and student-in-trouble interaction, and that the way this knowledge is made use of is retrospective-prospective is critical to that process. The activity of 'filling-in-the-form-of-using-infirmary' makes that interaction a 'normal visit', and makes the situated features such as time and space characteristic of school organization accountable to that process. Both of them, named 'ethnomethodology (EM) in infirmary' are critical to the school counselling.