A passive sampler for measurement of gaseous mercury has been developed and tested in laboratory experiments. The sampler has also been compared to active measurement during field campaigns at ambient background concentrations of mercury as well as at slightly elevated concentrations. The result compares favourably with Tekran measurements and show that the sampler can be used for monitoring low background concentrations of mercury as well as elevated concentrations. It is also suitable as a personal dosimeter in occupational health measurements. The present work was performed as a subtask within the EU funded project, Global Mercury Observation System (GMOS).