A new experimental set-up has been designed in order to study the spatial distribution of atoms and ions in a radiofrequency glow discharge (rf-GD) using optical emission spectroscopy (OES). The excitation/ionization processes that occur within the plasma are investigated through the measurement of different atomic and ionic emission intensities along the plasma plume. This information is also of great interest for the coupling optimization of the GD source to a mass spectrometer (i.e. optimal position for ion extraction). In this work, preliminary spatial resolved studies of the plasma in continuous and pulsed rf-GD-OES are shown. In particular, the influence of parameters such as applied power, pressure or duty cycle on the emission signals has been evaluated.