PURPOSE: To obtain a three-dimensional structure having many communicating air holes by forming the structure through random attachment of ring ceramics to each other in the captioned structure used for a hot air device and the like.

CONSTITUTION: A ring formed body 1 of ceramics is formed by extrusion of temporarily-burnt ceramic material, and after the formed body 1 is wetted with the ceramics slurry having the same composition with the formed body, many of them are thrown in a receptacle for burning at random, dried and burnt therein, thus a united ceramic structure 3 being obtained. Since the ring bodies 1 of ceramics are stuck to each other in the random directions and united in this way, a three- dimentional structure having many communicating air holes along apertures 4 can be obtained. Thus the porosity of the structure thus produced becomes very high, while the mass production thereof being easy.