The invention relates to the treatment of metals by pressure and to welding thereof by pressure. It is directed towards a method of manufacturing a multilayer cellular structure from materials capable of superplastic deformations, consisting of: joining sheet blanks of a filler made from titan alloy by means of welds that follow predetermined patterns; air-tightening the hollow between such blanks; inserting these blanks between sheet blanks of a skin; effecting forming through regulated pressure of a working medium; and solid-phase joining. To improve the quality of solid-phase joining the manufacturing is effected in two steps within a temperature range T1-Tp.t. where T1 is a temperature not exceeding the temperature of aging of tempered titan alloys, preferably 550 DEG C, and Tp.t. is the temperature of full polymorph transformation of the titan alloy. On the first step, the forming is made in such a way as to obtain a half-finished product with ready cells, and a physical contact is achieved between the joined surfaces of the sheet blanks. On the second step, the half-finished product is deformed with a degree of deformation epsilon of the joined sheet blanks. The grain size in the sheet blanks of the filler and/or of the skin is selected to meet the equation epsilon > epsilon min, where epsilon min is a minimal degree of deformation required to ensure the grain-boundary creep in the joining zone.