A memory that includes a memory device having a phase change layer that can be reset by using a reset gate is provided. A memory device includes memory elements arranged in two or more rows and two or more columns. Each memory element includes a pillar-shaped phase change layer, a reset gate insulating film surrounding the pillar-shaped phase change layer, and a reset gate surrounding the reset gate insulating film. The reset gates are connected in a row direction and in a column direction, and are heaters. The pillar-shaped phase change layers are electrically insulated from the reset gates.