The article offers an analysis of the “turn” in Martin Heidegger’s teachings about the truth. The concept of truth of the German thinker before and after the “turn” is revealed and the specifics of its transformation are explained. Criticizing the traditional understanding of truth in his early works, Heidegger connects his concept of truth with the reinterpretation of the ancient Greek ἀλήθειαas unconcealedness. Comparison of the concept of truth in the work “Being and Time” (§ 44) with its understanding in the pivotal article “On the Essence of Truth”, as well as in later works, leads tothe conclusion that after the “turn” the thinker has a rethinking of ἀλήθεια. Ἀλήθεια analytics is carried out through consideration of the following aspects: interpretation of the meaning of the prefix “α” in “Being and time” and later works, the ratio of concealment and disclosure in the interpretation ἀλήθεια of before and after the “turn”, the role of “reconquering” the truth from λήθη.