A support unit may include a plurality of heaters disposed in a matrix form in the support unit to heat a substrate, and a power supply unit for supplying power to the plurality of heaters, wherein a current applied to the plurality of heaters is controlled by switches connected to rows and columns of the matrix, respectively, and the switches connected to the rows of the matrix include first switches capable of controlling the current applied to the rows of the matrix and second switches connected in parallel with the first switches.