After a brief discussion of the reasons for the complete failure of a deterministic interpretation of quantum mechanics (§ 1)Niels Bohr's ideas on quantum mechanics are exposed. The importance of Bohr's idea on the necessity of combining the quantum-mechanical description of atomic objects with a classical description of the instruments is stressed (§ 2).It is pointed out, however, that the terminology used by Bohr often gives rise to misunderstandings and to a positivistic interpretation of his ideas. This, in turn, creates an opposition to the new ideas (de Eroglie school) (§ 3).In the following the concept of relativity with respect to observation means is introduced and it is stressed that relativity does not exclude objectivity (§ 4).The meaning of the term “instrument” as used in quantum mechanics is explained (§ 5).It is pointed out that wave-corpuscular duality is connected with the inherent possibility of the electron to manifest itself, according to the external conditions prevailing, as a wave, or as a corpuscle, or in an intermediate way. A more literal interpretation of duality based on some model is inadmissible (§ 6).The probabilistic description of the interaction of an atomic object with an instrument, resulting in a probability distribution for the measured quantity, is discussed and the primary character of probability in quantum mechanics is stressed (§ 7).If a subdivision of the experimental arrangement in a preparatory part, a working part and a registration part is possible, one can vary the last stage of experiment and obtain probability distributions referring to the same initial state. Since these are parametrically expressed in terms of one and the same wave function, this function is independent of the last stage of experiment. By making the corresponding abstraction one is led to the quantum-mechanical concept of state as described by a wave function (§ 8).The necessity of distinguishing in quantum mechanics the potentially possible from the accomplished is compared with the concepts of classical physics and with the notions of everyday life (§ 9).The nature of the statistical collective to which the quantum-mechanical probabilities refer is discussed and it is shown that the statistical character of quantum mechanics does not contradict the fact that this theory describes the properties of an individual object (§ 10).The role and position of the causality principle in quantum mechanics is discussed and the nature of the so-called “reduction of a wave-packet” explained (§ 11).The necessity of incorporating the new ideas in the materialistics philosophy and of a further development of dialectic materialism is stressed (§ 12).