To provide an autoclaved lightweight concrete (ALC) panel in which occurrence of crack caused by drying or carbonation after aging or through use is previously prevented.

After the ALC panel is aged, the sum total of the compression stress of a base material and the tensile stress of a reinforcement bar is controlled to ≥0.04% to <0.5%, preferably ≥0.18% to ≤0.4%. It is preferable that the coefficient of thermal expansion of the reinforcement bar is ≥1.20×10-5 to ≤2.50×10-5. It is preferable that the tensile stress is applied to the reinforcement bar part by a mechanical means during the aging in the autoclave.