PURPOSE: To prevent a powder of organic compound raw materials from scattering during evaporation to outside an evaporation source and to secure a stable evaporation amount of the organic compound raw materials at all times.

CONSTITUTION: Raw materials of an organic compound 2 are placed in an evaporation material container 1, around the outside of which a heater for heating evaporation materials 3 is wound. Also, a filter 4 comprising a 1mm- thick formed metal is mounted on the top of the container 1 which is heated by a heater 5 to over the evaporation temperature. Thermocouples 6 and 7 are provided. A powder of organic compound raw materials scattering from the evaporation surface is prevented by the filter 4 from further scattering to the outside of the evaporation material container 1 to produce an organic thin film having few pinholes. Clogging of the filter 4 by the powder is prevented by heating the filter 4 higher than the evaporation temperature.