The genre of the monoopera is still relatively young, but is already rather demanded both from composer's, performer's, and researcher's points of view. The most important of the semantic constants of the monoopera providing its genre uniqueness is the central value of the only character. Such concept as the comprehensive consciousness of the character (CCC) is introduced. All the surrounding we see through the "eyes of the character". Other characters who are virtually present in the monoopera function only as objects of CCC. Among the sets of the semantic areas of the monoopera caused by action of the semantic constant of a genre - "uniqueness" of the character -in the fixed, already created texts the complex of semantic areas of loneliness prevails. Such traditionalism in addressing this complex of semantic areas is caused by specifics of the widespread ideas of the genre of monoopera including, as a rule, mixture of concepts of loneliness represented only by one complex of semantic areas, and the monologicality being one of the key properties of the genre. Monologicality of CCC doesn't demand for the art realization of a subject and factual situation of loneliness. The loneliness becomes a semantic area only when it turns into CCC, the fact apprehended and realized by the identity of the character. Attention to the semantic area of loneliness can be explained through historical processes of formation of the genre of monoopera: chronological synchronism of emergence of the theory of the monodrama, the culminating in development of an expressionistic image of "the lost person", functioning of German "dramas of shout" ("Schrei-dramen") all that isn't accidental. A. Shnberg created the monoopera/monodrama "Expectation" which laid the foundation for understanding the monoopera as an independent genre. In the complex of semantic areas of loneliness in the monoopera such areas as an area of the compelled inaction, an area of epistolary genres and an area of "hidden places of the dimmed consciousness" come to light. The complex of semantic areas of loneliness, differs from other semantic complexes of the monoopera in what excludes involvement of the external alarm system realizing the contacts of CCC aimed outside and from the outside the observable. Theses of the article are illustrated by examples from monooperas by F. Poulenc ("A Human Voice"), G. Fried ("Anne Frank's Diary"), M. Tariverdiev ("Expectation"), and A. Spadavekkia ("The letter of the stranger").