In a NAND type nonvolatile memory device, a first insulating layer covers a common drain region formed in a string active region and a peripheral active region. A second insulating layer covers the first insulating layer. A bit line plug penetrates the first and second insulating layers and is connected to the common drain region. A peripheral lower plug penetrates the first insulating layer and is connected to the peripheral active region. A peripheral upper plug penetrates the second insulating layer and is stacked on the peripheral lower plug.