Lit. pure fire hall. A hall for the preparation of food to be offered to the gods at Ise Jingu 伊勢神宮. The character 忌 imi is usually associated with mourning, taboo, or misfortune. However, a lesser known meaning used here entails keeping one's mind and body pure. Thus, the food ingredients prepared in the imibiyaden must be of utmost purity. The water is drawn from a sacred well and the fire is made in the ancient way i.e., by rubbing two sticks together. At Ise Jingū the fire is ignited every night and morning by twisting a stick of wild loquat against small blocks of cypress with an implement called mihikirigu 御火鑚具. The high priest who prepares the "pure fire" is secluded while performing the ritual (see *sanrōsho 参籠所). This ritual is also performed in the Imperial Palace prior to important ceremonies like the rice tasting ceremony, nīnamesai 新嘗祭, when the Emperor offers the newly harvested rice to the gods and then eats a little himself.
There are imibiyaden in both the Naikū 内宮 and Gekū 外宮 at Ise. The Naikū imibiyaden is located west of the Daikūin 大宮院, the most sacred area in the shrine, and faces south. According to a Kamakura period record, the Naikū imibiyaden was surrounded by a fence and had a Shinto gate *torii 鳥居 on its south side. The building was four-bays long and roofed with cypress bark *hiwadabuki 桧皮葺. The eastern half of the interior had an earthen floor while the western half was covered with boards. In the Edo period, it was 818 cm long by 455 cm wide. The roof was thatched and the fence and torii had disappeared. Before World War II, the roofing was made of thinly cut shingles *kokerabuki 柿葺. Nowadays, the imibiyaden is almost three times its former length and considerably wider. The roof is gabled and covered with boards.
The Gekū imibiyaden is located to the north of the most sacred inner precinct of the Shrine and also faces south. In the Edo period, this building measured 909 cm by 364 cm. Small aisle-like additions *hisashi 廂 were attached to the north and south sides. Only the eastern half, called ōsudono 御臼殿, was surrounded by a fence. The western half was called either *mikeden 御饌殿 or okamaya 御竈屋. Board roofing was used. Before World War II, the Gekū imibiyaden was enlarged by 545 cm to 1872 cm. Nowadays its gable roof *kirizuma-zukuri 切妻造 is covered by wide boards and battens. Walls are made of horizontal planks set between the posts which form the framework and support the roof structure. A fence protects the west end of the building. There is an outlet for smoke above, and usually near the second bay from the west end. This gives the structure the appearance of a simple folk dwelling.