Background. Perfluorocarbon (PFC) has been widely used in the treatment of respiratory diseases; however, PFC content of the breathing gases remains unknown. Therefore, we developed an absorber using PFC selective zeolites for PFC measurement in gases and investigated its accuracy. Methods. To generate a breathing gas with different PFC contents a heated flask was rinsed with a constant air flow of 4 litre·min^-1 and 1, 5, 10, and 20 ml of PFC were infused over 20 min using an infusor. The absorber was placed on an electronic scale and the total PFC volume was calculated from the weight gain. Results. Steady-state increase in weight was achieved 3.5 min after stopping the infusion. The calculated PFC volume was slightly underestimated but the measuring error did not exceed -1% for PFC less than 1 ml. The measurement error decreased with increasing PFC volume. Conclusions. This zeolite absorber is an accurate method to quantitatively determine PFC in breathing gases and can be used as a reference method to validate other PFC sensors.