A mounting table is provided. The mounting table includes an electrostatic chuck configured to mount thereon a target object and attract and hold the target object using an electrostatic force, and a gas supply line configured to supply a gas to a gap between the target object mounted on the electrostatic chuck and the electrostatic chuck via the electrostatic chuck. The mounting table further includes at least one irradiation unit configured to irradiate light having a predetermined wavelength to the gas flowing through the gas supply line or to the gas supplied to the gap between the target object and the electrostatic chuck to ionize the gas.