A method for manufacturing a vacuum heat insulating material includes: a collecting step for extruding heat-deposited resin in a continuous state from a plurality of aligned nozzles and collecting on a conveyer as a plurality of organic fibers; a reeling step for feeding the conveyer at a predetermined speed, and producing an organic fiber assembly in a reeled sheet state by applying pressure with a roller and applying heat-deposition; a core material processing step for making a core material having a predetermined size by cutting an end face of the organic fiber assembly produced by the reeling step; a decompressing step for inserting the core material into an outer cover material from an insertion opening and decompressing an inside to an almost vacuum; and an outer cover material sealing step for sealing the insertion opening of the outer cover material the inside of which is decompressed to the almost vacuum.