Protective sheet application apparatus and method

A protective sheet application method for applying a protective sheet on a front surface of a substrate having irregularities on a side of the front surface, comprising:

• a substrate mounting step of mounting, in a vacuum chamber that is separable into an upper housing and a lower housing and includes a support table disposed inside the lower housing and configured to mount the substrate thereon, a first depressurization unit and a first open-to-atmosphere unit connected to the lower housing, and a second depressurization unit and a second open-to-atmosphere unit connected to the upper housing, the substrate onto the support table with the front surface directed upward in a state that the lower housing and the upper housing are separated from each other;
• a space separation step of placing the protective sheet on the substrate and the lower housing with the protective sheet opposing the front surface of the substrate mounted on the support table, and unifying the lower housing and the upper housing with the protective sheet held between the lower housing and the upper housing, so that a space in the vacuum chamber is separated into a first compartment surrounded by the lower housing and the protective sheet and a second compartment surrounded by the upper housing and the protective sheet;
• a depressurization step of depressurizing the first compartment to a predetermined air pressure by the first depressurization unit and depressurizing the second compartment by the second depressurization unit;
• a protective sheet close-contacting step of opening the depressurized second compartment to the atmosphere by the second open-to-atmosphere unit to bring the protective sheet into close contact with the substrate by a predetermined force such that the substrate follows the irregularities of the front surface of the substrate;
• and
• a substrate unloading step of, after the protective sheet close-contacting step, opening the pressurized first compartment to the atmosphere by the first open-to-atmosphere unit to separate the lower housing and the upper housing from each other, and unloading the substrate with the protective sheet kept in close contact therewith from the vacuum chamber.