An organic light-emitting device including a magnetoresistive element including a first magnetic layer, a second magnetic layer, and a separation layer disposed between the first magnetic layer and the second magnetic layer, an organic light-emitting element electrically connected to the magnetoresistive element, wherein the organic light-emitting element comprises a first electrode, a second electrode, and an organic light-emission layer disposed between the first electrode and the second electrode, a magnetic field applying unit configured to apply a magnetic field to at least the magnetoresistive element, and optionally, to the organic light-emitting element, a power source configured to supply a current between the magnetoresistive element and the organic light-emitting element, and a current source configured to apply a current between both terminals of the organic light-emitting element, wherein light-emission characteristics of the organic light-emitting device are changed depending on a direction and intensity of a current passing through the magnetoresistive element due to the power source and a direction and intensity of a current passing through the organic light-emitting element due to the power source and the current source.