An organic electroluminescent device, a manufacturing method thereof and an evaporation apparatus are provided. The manufacturing method for the organic electroluminescent device includes: forming, on a base substrate, a first electrode layer; performing vacuum evaporation on an organic functional layer material to be evaporated, and performing a heat treatment, during the evaporation of the organic functional layer material to be evaporated, on the base substrate on which the first electrode layer is formed, so as to form an organic functional layer on the base substrate on which the first electrode layer is formed; and forming, on the base substrate on which the organic functional layer is formed, a second electrode layer.