Several fundamental experiments were performed on adsorption process of 86Kr storage at the ordinary condition of temperature and pressure. A long-term test for storage was then performed with radioactive 85Kr and the safety was confirmed by hot run of 38 days. Of many adsorbents adopted in preliminary experiments, the largest amount of adsorbed Kr was AW-500 (16.4 cc STP/g) among molecular sieves and Tsurumi HC-30E (33.2 cc STP/g) among charcoals. The amount of adsorbed Kr decreased slightly with the addition of Rb and with the irradiation of the order of 105 Mrad. It was found that adsorption rate is effected larger by Xe than by air. In 85Kr storage test of 100 Ci, the pressure in storage vessel varied in the range of about ±4%, and the 85Kr leak rate from the vessel was the order of 10−12cc·atm/s. It was found that there is no considerable temperature rise due to β disintegration. From these results, the adsorption process may be useful for storage of 85Kr for long-term.