To provide a method for producing a lightweight cellular concrete panel in which cavity parts formed above reinforcements are reduced.

In the method, the reinforcements mainly comprising main reinforcements and sub-reinforcements of the lightweight cellular concrete panel are set in parallel in a form with the sub-reinforcements arranged vertically. Aqueous raw material slurry prepared by adding water and aluminum powder into a raw material mainly comprising a slicate raw material and a lime raw material is cast into the form. After the expansion of the slurry by the foaming of aluminum is finished, and the slurry is semi-cured, the semi-cured slurry is demolded, cut corresponding to the reinforcements, and cured in an autoclave. The height of the semi-cured slurry in the form is adjusted to be 105-120% of the finished lightweight cellular concrete panel.