In many applications, sintering of particles is required to improve device efficiency. In particular, sintering of TiO2 nanoparticles attracts great attention because of growing of solar cell applications, and conventional sintering using an electrical furnace has been widely used for sintering of nanoparticles. In this study, conventional and microwave sintering processes were investigated to examine the possibility of application of microwave sintering method to TiO2 nanoparticles. Microwave sintering of TiO2 nanoparticles showed promising results compared with the conventional heat treatments in terms of surface area, crystalline phase, optical property and morphology. Considering the short sintering time, the microwave method could be more advantageous than the conventional sintering method in some application areas.