PURPOSE: To obtain such a block as having a sufficient rigidity without thickening as before and providing with high water-permeability by forming a permeable ceramic block of an upper porous substance with open cells and a lower dense substance with almost no air holes.

CONSTITUTION: A permeable ceramic block 10 is constituted of an integral sintered substance of the upper porous substance 1 with open cells and the lower dense substance 2 with almost no air holes. Good mechanical strength is maintained by the lower dense substance 2, and a good appearance of surface condition and water-permeability are held by the upper porous substance 1.