An apparatus for manufacturing a polycrystalline silicon thin film, including a crystallization container filled with silicon oil, crystallization electrodes spaced apart from the crystallization container, and a conductive plate positioned between the crystallization electrodes and connected with the crystallization electrodes. Because an insulating layer between the amorphous silicon thin film and the conductive plate is formed by using silicon oil filled within the crystallization container, Joule-heating induced crystallization (JIC) can be performed through a simpler manufacturing process.