PURPOSE: To obtain an apparatus capable of manufacturing a large number of hollow bodies at low cost by the use of thermoplastic resin film extruded from a T die in a molten state.

CONSTITUTION: Two sheets of thermoplastic resin films extruded in a molten state from a T die 6 provided on the tip end of an extruding machine 4 are sent between the surfaces of a pair of cooling rollers 7, 8 having a plurality of depressions 1 formed on the circumferential direction of its outer periphery, so that similar depressions are made on the surfaces of both the molten films by suction of suction holes provided on the depressions 1, then a hollow body is manufactured by sticking both the molten films together at a joint part of both the cooling rollers.