This paper analyzes the context of the existence of the mask in ancient Greece, the author examines the funeral masks, zoomorphic masks, masks of mythological characters, etc., considering their functions in this social and cultural context. In addition, the author examines the theatrical masks history in V century BC. Stressing the importance of the sacred basics of a theatrical mask, the author analyzes the impact of the artistic traditions of the ancient Greeks on its aesthetic form. In conclusion the author emphasizes that the conventionality as an artistic technique of ancient art, which found expression in the theatrical mask, gave additional opportunities to the Greek playwrights to address the audience by means of «non-verbal language».