A first bubble and the second bubble comprises in a thermoplastic resin sheet, said second bubble, said first mean diameter is greater than the bubble, and the thickness direction of the thermoplastic resin sheet thermoplastic resin foam sheet are distributed in central; and, when forming the resin sheet 13 molded by extruding a thermoplastic resin containing a dispersed plasticizer, so that the shear stress in the resin sheet 13 to be extruded is produced to extruded and then heating the resin sheet 13 is foamed after impregnating the inert gas in the resin sheet 13, to generate a first bubble 11 in the thickness direction of both surface and first in the thickness direction central portion by generating second bubble 12 average diameter is larger than the bubble 11 to form a thermoplastic resin foam sheet 10, by slicing a region in which the second bubble 12 is generated by the slicing blade 20, thermoplastic Manufacturing method for forming a thin film sheets 14 and 15 of thermoplastic resin foam is divided in a plane intersecting the fat foam sheet 10 in the thickness direction.
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