Wiseman aims his camera at the Neiman-Marcus way of life

The mystique is almost as fascinating as the Frederick Wiseman mystique. In The Store (PBS, Wednesday, Dec. 14, 9-11 p.m., check local listings for premiere and repeats)m, acclaimed filmmaker Wiseman focuses his ''reality fiction'' camera on the Neiman-Marcus, the famous Dallas emporium. Without narration and seemingly without point of view, but with an instinctive, incisive eye for truth, Mr. Wiseman's new film is another in his continuing studies of American institutions and attitudes.

''The Store'' is Wiseman's first color film. Slowly, quietly, almost subliminally, he manages to introduce the viewer to an unusual department store which almost constitutes a life for its customers, its employees, its executives. This is also Wiseman's first close look at America's rich - and he makes it more an X-ray than a glamour photo.

Viewers will hear about the almost unbelievable prestige associated with the store as customers, buyers, salespeople, executives, even job applicants, reveal as much about themselves as they do about Neiman-Marcus in their moments before the camera. Especially pitiful is a segment in which an applicant for an executive position plaintively explains how much the store means to her - a segment that reveals a lot about the paternalistic side of American capitalism and how it affects individuals.

The film is two hours long, rather short for a Wiseman masterwork, and not a second drags as viewers are allowed to enjoy the pleasures of a leisurely Christmas shopping spree, without the holiday hordes. The climax - the 75th anniversary party for Stanley Marcus, attended by such notables as Lady Bird Johnson and Liz Carpenter, with Art Buchwald as host - is a fitting culmination to what may seem on the surface to be a gigantic tribute to a department store but which is actually a sly study of free enterprise in action.

At the big party, Stanley Marcus of Neiman-Marcus proudly sings of his life's accomplishment - that ''I did it my way.'' Well, Frederick Wiseman can rejoice as well that once again he has done it his way. He has delved deeply and wisely into seemingly superficial subject matter and come up with a subtly informative - and incidentally entertaining - tract that will likely be of sociological importance for generations to come.