Abstract: Disclosed is a thermoelectric device, including a flexible substrate having a zigzag configuration in which a vertical cross-section in a longitudinal direction of one surface thereof includes peaks and valleys and a thermoelectric material line positioned on the flexible substrate and configured to include a p-type thermoelectric material and any one of an n-type thermoelectric material and an electrode material, which are alternately continuously disposed, wherein any one of the n-type thermoelectric material and the electrode material is in contact with the p-type thermoelectric material at the peaks and the valleys. The thermoelectric device, having a zigzag configuration, is highly flexible and lightweight, and a thermoelectric material in film form can be utilized to realize a vertical temperature difference, and thus the thickness of the device can be freely adjusted regardless of the film thickness, thereby easily maintaining a large temperature difference even without a heat sink.