To provide a central ventilating apparatus and a ventilating structure wherein wasteful use of thermal energy is reduced.

There are provided in a central ventilating apparatus for ventilating a building a total heat exchanger 62 for exchanging total heat between exhaust exhausted to the outside of the building and fresh air supplied into a room and total heat exchange release means 80 for releasing total heat exchange operation of the total heat exchanger 62. Hereby, wasteful use of thermal energy is reduced by not actuating the total heat exchange release means 80 in a cooling interval and a heating interval but performing total heat exchanger between fresh air and exhaust in the total heat exchanger 62, recovering thermal energy of exhaust, and further in an intermediate interval actuating the total heat exchange release means 80, and releasing the total heat exchange operation in the total heat exchanger 62, and taking in fresh air not heat exchanged with exhaust into the room as it is.