Analysis of a blinker, observed with the SUMER/SOHO spectrometer in the C ii 1036.34 Å, C ii 1037.01 Å, O vi 1037.61 Å lines and in C i continuum, is presented. We find that the blinker is highly pronounced in both the chromosphere and transition region. Intensities of chromospheric and transition region lines behave similarly although the blinker is more pronounced in the upper transition region.