A memory array comprising: a plurality of first wires (32, 33); at least one second wire (30, 31) crossing the first wires (32, 33); and a plurality of memory elements (34 - 37) provided in correspondence with respective intersections of the first wires (32, 33) and the at least one second wire (30, 31) and each having a drain electrode and a source electrode arranged spaced apart from each other, a gate electrode connected to one of the at least one second wire (30, 31), and an insulating layer that electrically insulates the drain electrode and the source electrode and the gate electrode from each other, the first wires (32, 33), the at least one second wire (30, 31), and the first wires (32, 33), the at least one second wire (30, 31), and the memory elements (34 - 37) being formed on a substrate, either the drain electrode or the source electrode being connected to one of the first wires (32, 33), at least one of the memory elements (34 - 37) having an applied layer in an area between the drain electrode and the source electrode, the memory elements (34 - 37) including two kinds of memory elements (34, 35) different from each other in electrical characteristics between the drain electrode and the source electrode by the applied layer, information to be recorded being determined by arrangement with any combination of the two kinds of memory elements (34, 35), wherein the applied layer is formed of a semiconductor material applied to the area between the drain electrode and the source electrode and is a first semiconductor layer or a second semiconductor layer, the first and the second semiconductor layers (24, 27) being different from each other in electrical characteristics, out of the two kinds of memory elements (34, 35), one kind of memory element is a memory element having the first semiconductor layer, whereas another kind of memory element is a memory element having the second semiconductor layer, and the one kind of memory element and the other kind of memory element record respective pieces of information different from each other by a difference in electrical characteristics between the first semiconductor layer and the second semiconductor layer, characterized in that the first semiconductor layer and the second semiconductor layer each contain carbon nanotubes as the semiconductor material, and a concentration of carbon nanotubes of the second semiconductor layer is higher than a concentration of carbon nanotubes of the first semiconductor layer. a plurality of first wires (32, 33); at least one second wire (30, 31) crossing the first wires (32, 33); and a plurality of memory elements (34 - 37) provided in correspondence with respective intersections of the first wires (32, 33) and the at least one second wire (30, 31) and each having a drain electrode and a source electrode arranged spaced apart from each other, a gate electrode connected to one of the at least one second wire (30, 31), and an insulating layer that electrically insulates the drain electrode and the source electrode and the gate electrode from each other, the first wires (32, 33), the at least one second wire (30, 31), and the first wires (32, 33), the at least one second wire (30, 31), and the memory elements (34 - 37) being formed on a substrate, either the drain electrode or the source electrode being connected to one of the first wires (32, 33), at least one of the memory elements (34 - 37) having an applied layer in an area between the drain electrode and the source electrode, the memory elements (34 - 37) including two kinds of memory elements (34, 35) different from each other in electrical characteristics between the drain electrode and the source electrode by the applied layer, information to be recorded being determined by arrangement with any combination of the two kinds of memory elements (34, 35), wherein the applied layer is formed of a semiconductor material applied to the area between the drain electrode and the source electrode and is a first semiconductor layer or a second semiconductor layer, the first and the second semiconductor layers (24, 27) being different from each other in electrical characteristics, out of the two kinds of memory elements (34, 35), one kind of memory element is a memory element having the first semiconductor layer, whereas another kind of memory element is a memory element having the second semiconductor layer, and the one kind of memory element and the other kind of memory element record respective pieces of information different from each other by a difference in electrical characteristics between the first semiconductor layer and the second semiconductor layer, characterized in that the first semiconductor layer and the second semiconductor layer each contain carbon nanotubes as the semiconductor material, and a concentration of carbon nanotubes of the second semiconductor layer is higher than a concentration of carbon nanotubes of the first semiconductor layer.