A high-density data storage medium, a method of manufacturing the data storage medium, a high-density data storage apparatus, and methods of writing data on, and reading and erasing data from the data storage medium by using the data storage apparatus are provided. The data storage medium includes a lower electrode, an insulation layer deposited on the lower electrode, a photoelectron emission layer deposited on the insulation layer and having a plurality of protrusions from which photoelectrons are emitted due to collisions between the protrusions and photons, and a dielectric layer deposited on the photoelectron emission layer and storing the photoelectrons emitted from the photoelectron emission layer. The data storage apparatus includes a stage supporting a data storage medium, which includes a lower electrode, an insulation layer deposited on the lower electrode, a photoelectron emission layer deposited on the insulation layer and having a plurality of protrusions from which photoelectrons are emitted due to collisions between the protrusions and photons, and a dielectric layer deposited on the photoelectron emission layer and storing the photoelectrons emitted from the photoelectron emission layer, a scanner driving the stage, a probe placed over the data storage medium and including a tip forming an electric field with the data storage medium and a cantilever supporting the tip placed at its one end so as to maintain a predetermined distance between the data storage medium and the tip, a circuit unit applying a driving signal, a data write signal, and a data erase signal to the scanner and the probe and detecting a data read signal, and a light source irradiating light on the data storage medium.