To clarify roles of maintenance mechanics of agricultural machines at the Shimane University educational and experimental farm, We analyzed working times required for maintaining and repairing of the machines from 1996 to 2000. Since a grain combine was intermittently and most frequently used through the year, the maintaining time for it was the longest in all machines. On the other hand, the longest repairing time was consumed for a speed sprayer, which was used very often and needed frequently urgent repairs. An investigation by the questionnaire for the students who used these agricultural machines in their farm exercises revealed the following: the farm exercises were important and beneficial for almost all students, however about 30% of them pointed out some mechanical and operative dangers during the exercises. The results indicate that the students should be educated in the farm with more careful and safer considerations. It became impossible to have any maintenance-specified mechanics of agricultural machines in our University farm because of a recent big reduction of the total technical officers in the University. Therefore, it is very essential for all staffs to be capable of operating carefully and maintaining the machine in order to use them as effectively as possible.