To provide an earth retaining concrete block and its installation method exerting an earth retaining function as before and a very good drainage function of underground water and forming a hardly collapsable soil wall face.

An insertion opening section 4 for inserting weights 1 is provided on a block body 3 having a storage section 2 capable of storing many lump bodies such as stones 1A and concrete wastes 1B as the weights 1. A plurality of flow holes 5 communicating the storage section 2 with the outside are dispersively provided on the block body 3 as small holes so that the weights such as the stones 1A and concrete wastes 1B stored in the storage section 2 cannot pass through them.