A stage is provided on which is mounted a substrate that has a concavo-convex portion such as a circuit formed on the underside thereof. A channel 3 through which a coolant such as water flows is formed in a stage 1. An annular flange portion 4 is formed on the top surface of the stage 1. The inner side of the flange portion 4 forms a concave portion 5. The top surface of the flange portion 4 is provided with a smooth finish in order to mount a peripheral section of the underside of a substrate W thereon. Holes through which are passed three positioning pins 6 and lift pins 7 are provided in the flange portion 4 at regular intervals in the circumferential direction.
