Provided are a hollow spring and a method for manufacturing the hollow spring, whereby durability can be improved, and the efficiency of polishing the inner surface of a spring material can be improved. A blasting apparatus (100) uses a straight and hollow spring material (W). The length of the spring material (W) is set to 1.5 m to 3.5 m, and the inner diameter is set to no more than 10 mm (F). Polishing the inner surface of the spring material (W) involves carrying out a first blasting process and a second blasting process in sequence. In the first blasting process, an abrasive is discharged through an opening (Wa) of the spring material (W) and suctioned from an opening (Wb). In the second blasting process, the abrasive is discharged through the opening (Wb) of the spring material (W) and suctioned from the opening (Wb). The inner surface of the spring material (W) can thus be prevented from becoming trumpet-shaped. By properly setting a discharge pressure and suction pressure etc., differences in stock removal in the middle and at the ends of the inner surface of the spring material (W) can be minimized.