The importance of face-to-face informal communication is well recognized. The ‘irori’ is a Japanese-traditional little sitting space or room with a fire burning which affords relaxation and intimacy among a family. We, adopting the ‘irori’ as a metaphor, have designed and developed a cyber-space called IRORI as an IT-based space that catalyzes face-to-face informal communication among members of a small organization. We conducted evaluations of the IRORI by user experiments. The results of the experiments suggested that the IRORI brought about relaxation and conversation catalysis.