The article deals with the question of Plato's reception in Heidegger's philosophy. In particular, the research focuses on the question of how Heidegger interpreted the idea of the good from Plato's "State". Here a number of difficulties important for the history of philosophy arise. What is the ontological status of the idea of good? How is the idea of the good connected with the demiurge from the dialogue "Timaeus"? On the one hand, it is well known that the late Heidegger criticized Plato and all European metaphysics, which was and remains Platonism. On the other hand, the early Heidegger clearly presents an attempt to master the shining heights of Platonism: the question of the meaning of being needs an angle from which a definite answer can be highlighted – and Heidegger borrows this angle from Plato. Just as the good endows existence with being and truth, so the understanding of being is possible from time, because it is temporality that is the condition for understanding being, it highlights its meaning. And if Plato's being "pounces" on the good, or on the one, then for Heidegger, time is such a condition. This line of thought, fundamental to the whole project of fundamental ontology, is directly related to the philosophy of Plato, who for the first time was able to rise so high as to become ἐπέκεινα τῆς οὐσίας, to see things as if from the outside, i.e. in the light of the transcendent idea of good. Nevertheless, Heidegger criticizes Plato, which allows us to raise the question: how did Heidegger understand Platonic ἐπέκεινα τῆς οὐσίας and the doctrine of the good? It is impossible to answer this question unequivocally, since Heidegger approached this question from different sides and at different times interpreted this most important position of the Greek thinker in different ways. Nevertheless, the main remarks can be reduced to two: (1) the good was conceived by Plato as something moral and therefore mixed with the existing, (2) the good subordinates the being, brings it under fitness.