WAFER PLACEMENT TABLE

A wafer placement table includes a ceramic plate having a wafer placement surface on an upper surface, and a cooling plate provided on a lower surface of the ceramic plate. The cooling plate is made of a material having a lower thermal conductivity than Al. A length between an upper surface of a refrigerant flow path and the wafer placement surface is not constant and varies as being long in one part and short in another part. A flow-path cross-sectional area of the refrigerant flow path is not constant and varies as being small in one part and large in another part. An aspect ratio defined as a ratio of a vertical length to a horizontal length of a flow-path cross section of the refrigerant flow path is not constant and varies as being small in one part and large in another part.