To provide a method for confirming an attendance status including a tardiness and an early leaving without any notice by only being installed in a computer.

Students are required to transmit their own identification information and keywords different in each case more than once from their mobile terminal during school hours. The information and the keywords received by the existing mail server are read from the computer of a class teacher in charge. When the keyword transmitted by the student is identical to a keyword specified by the teacher at each transmission, the student is determined to be in the class at a transmission time. The student in all the transmission time is determined as an attender, the student in the class other than the first transmission time is determined as the late arrival, and the student not in the class other than the first transmission time is determined as leaving without any notice. Based on this acknowledgment, the information of the readout, the attending, the late arrival, and the leaving without any notice from the mail server are recorded and stored in the computer.