A memory device according to an embodiment includes a fluid layer extending in a first direction, a particle in the fluid layer, a first control electrode made of a first material, a first insulating film provided between the fluid layer and the first control electrode, a second control electrode made of a second material and provided to be spaced apart from the first control electrode in the first direction, a second insulating film provided between the fluid layer and the second control electrode, a third control electrode made of a third material different from the first material and the second material and provided between the first control electrode and the second control electrode, and a third insulating film provided between the fluid layer and the third control electrode.