A device for controlling a temperature of a mounting table for mounting thereon a target object includes a first and a second coolant passageway provided at the mounting table, a coolant circulator for circulating a coolant in the first and the second coolant passageway, channels, a coolant temperature controller for raising or lowering the temperature of the coolant, a channel switching unit for connecting, blocking and changing the channels among a first to a fourth port; and a channel controller. Various modes for controlling a temperature of the mounting table can be obtained by combining an ON/OFF state of the heating operation in the coolant temperature controller with ON/OFF states of opening/closing valves in the channel switching unit under the control of the channel controller.