A substrate supporting apparatus includes a rotatable chuck, a first mass flow controller, a second mass flow controller, a plurality of locating pins and guiding pillars, and a motor in which the rotatable chuck defines a plurality of first injecting ports and second injecting ports, the first injecting ports are connected with a first gas passage for supplying gas to the substrate and sucking the substrate by Bernoulli effect, the second injecting ports are connected with a second gas passage for supplying gas to the substrate and lifting the substrate, the first and the second mass flow controllers are respectively installed on the first and the second gas passages, the plurality of locating pins and guiding pillars are disposed at the top surface of the rotatable chuck and every guiding pillar protrudes to form a holding portion, and the motor is used for rotating the rotatable chuck.