PURPOSE: To provide a banking foamed body block suitable to a weak ground where underground water is easy to teach which can be easily constructed without requiring an anchor or concrete floor board, is never carelessly floated even when laid in a position lower than the underground water level, and causes no lack of strength.

CONSTITUTION: In a banking foamed body, which is longitudinally and laterally arranged on the ground, and laid in the vertically laminated state, concrete as a weight adding material is filled in through-holes 2, 3 having gravity acting surfaces 4 forming the inclined surfaces having a normal gradient. The whole specific gravity of each banking foamed body block is set within 0.5-1.8.