The article deals with a method of making use of a historical document in the instruction of History at the secondary school, not only as a concrete implement but first as a means of the development of theoretical thinking and active attitude of a pupil at his acquiring historical knowledge at school. An analysis of the method Is in connection with an actual problematic of new solving the learning matter of the history at the socialist secondary school; therefore this subject matter is to be qualitatively differentiated from the learning matter of the basic school, and it must be enabled to introduce pupils in the beginnings of the methodology of historical science; it should also make the pupils possible to acquire elementary forms of learning historical facts and lawfulness. The article bases on an experiment with historical documents at various secondary schools; this experiment has made clear the supposition that by this method it is possible to achieve a very good educational effect and that, on a large scale, it may be asserted as one of successful methods in the History at the secondary school.