Abstract: A pair of first and second concrete layers (1, 2) spaced away from each other by a certain distance are connected to each other through a corrugated plate (3) having a uniform magnitude of amplitude so that there are formed a space between the concrete layers (1, 2). A weight of a concrete-made panel is decreased by this hollow structure. A corrugated plate (3) is designed to have a trapezoidal cross-section of rectangular corrugation. By sinking mountain and valley portions of the corrugated plate into the first and second concrete layers (1, 2), the concrete-made panel can have enhanced compressive strength in a direction of corrugation of the corrugated plate (3), and have enhanced rigidity because of diagonal members of a truss which keeps the concrete-made panel being kept to be a plane.