An electrostatic chuck assembly, including an electrostatic chuck on which a substrate is loaded; a channel that provides a flow passage for coolant in the electrostatic chuck, the channel having a first opening at a first end corresponding to a center of the substrate and a second opening at a second end corresponding to an edge of the substrate; and a valve box to control a flow direction of the coolant in the channel, the valve box including a first supply valve to control an introduction of the coolant into the first opening; a first return valve to control a drainage of the coolant from the second opening; a second supply valve to control an introduction of the coolant into the second opening; and a second return valve to control a drainage of the coolant from the first opening.