gel state plastic material for example high density polyethylene hdpe low density polyethylene ldpe polypropylene pp and polyethylene pe is injected into a parison tube 102 through an injection tube 106 of the parison 100 next as shown in fig3 b air is blown through a nozzle 104 provided at a center of the parison tube 102 while the left right molds 10 and 22 are closed next the injected gel state plastic material is molded at a predetermined temperature and pressure and then air blowing stops thus as shown in fig4 the footwear last 200 whose interior is hollow that is having a cavity part 202 is manufactured the air blowing can be performed even when the left right molds 10 and 22 are closed in the above description blowing position is set to a toe side of the footwear last however it is obvious that the blowing position can be set to a heel side of the footwear last a concrete condition for example general injection pressure or molding temperature is shown in table 1 fig4 is a cross sectional view illustrating a structure of the footwear last manufactured using the injection blow molding method according to the present invention referring to fig4 the inventive footwear last 200 is of a structure whose interior is hollow and is integrally provided in entirety in other words the footwear last 200 has the cavity part 202 inside not being.