The aim of the present study was to investigate the thermal injury in the liver after a minimally invasive electrosurgery technique with a copper-doped diamond-like carbon (DLC-Cu) surface coating. To effectively utilize electrosurgery in a clinical caner setting, it is necessary to suppress the thermal injury to adjacent tissues. The surface morphologies of DLC-Cu thin films were characterized using scanning electron microscopy and transmission electron microscopy. Three-dimensional liver models were reconstructed using magnetic resonance imaging to simulate the electrosurgical procedure. Our results indicated that the temperature decreased significantly when minimally electrosurgery with nanostructured DLC-Cu thin films was used, and that it continued to decrease with increasing film thickness. In an animal model, thermography revealed that the surgical temperature was significantly lower in the minimally invasive electrosurgery with DLC-Cu thin film (DLC-Cu-SS) compared to untreated electrosurgery. In addition, DLC-Cu-SS created a relatively small thermal injury area and lateral thermal effect. These results indicated that the biomedical nanostructure coating reduced excessive thermal injury, and uniformly distributed temperature in the liver.