To provide a manufacturing method of a concrete block capable of fixing a net to the concrete block easily and certainly.

An upper form 3 for forming a through-hole Ka is arranged above the bottom part of a bottomed lower form 1 composed of the bottom part 11 and a side part 12 to manufacture the concrete block 5 (5A) having the through-hole Ka. A net member 2 is supported between the bottomed lower form 1 and the upper form 3 in a pressure contact state and the space S formed by both of them is filled with concrete to embed the end part of the net member 2 in the concrete block to fix the same.