A 61-year-old Japanese man developed nephrotic syndrome (NS) due to idiopathic membranous glomerulonephritis (MGN). He received immunosuppressive therapy for two years, including prednisolone, cyclophosphamide, and cyclosporine A, but the NS persisted. Low-density lipoprotein apheresis (LDL-A) was initiated at a frequency of twice a month and continued for 9 years (203 sessions in total). His proteinuria reduced to less than 1 g daily after 9 years. LDL-A was stopped, and the NS has not relapsed for five years. This case suggests that long-term LDL-A therapy may be a treatment option for idiopathic MGN refractory to immunosuppressive therapy or short-term LDL-A.