To protect a natural ecological environment by providing a permeable concrete part in which a number of continuous minute voids are formed in a block body, and providing a soil lump in the inside of the permeable concrete part.

A stay part 22 is provided on the rear face side of a front face part 21 so as to be extended rearward, and a stay tail part 23 extending the horizontal direction is provided on the rear end of the stay part 22 to form a block part 2. A number of continuous minute voids are provided on the surface side of the front face part 21 of the block body 2, and a permeable concrete part 3 in which a soil lump 4 is provided is provided to form a concrete block 1. When the block 1 is laid on a river to construct a revetment, the soil lump 4 collapses due to river water, rainwater or the like to flow out, flows in the outer voids or soil particles or dust dispersing in the atmosphere flows in the voids of the permeable concrete part 3 to form the thin film of soil. Thereby since a micro-organism and a small organism breed, a natural ecological environment can be protected.