A cup assembly for holding a sample to be analyzed spectrochemically, includes a tubular longitudinal member which is disposed symmetrical about a central axis. The tubular member extends longitudinally between a first end and a second end. An indented peripheral flange is defined at the second end. The indented flange has an inverted L shaped cross-section. An annular collar extends longitudinally between a first end and a second end. An internal peripheral flange is defined at the first end. The internal flange has an inverted L shaped cross-section complementing the indented flange of the tubular member. When a substantially thin film is interposed between the second end of the tubular member and the first end of the annular collar, the film is retained between the sample cell body and the collar between the indented flange and the internal flange. The cup may have a funnel shaped sample retaining chamber.