Provided is a memory device including a substrate, a stack structure on the substrate, a contact, and a supporting pillar. The stacked structure includes a plurality of conductive layers and a plurality of insulating layers stacked alternately on each other. The contact is connected to one of the plurality of conductive layers of the stack structure. The supporting pillar penetrates the stack structure and is disposed around the contact. The supporting pillar includes a body portion and a plurality of extension portions. The body portion is arranged around a first side of the contact. The plurality of extension portions are located on two sides of the body portion. A length of each of the extension portions is greater than a width of the contact, and one of the extension portions is disposed around a second side of the contact.