With respect to a work obtained by joining a semiconductor wafer and a supporting member to each other via a both-faced adhesive sheet having heating separability, the surface of the supporting member is suction-held at a suction stage and is heated, thereby making the adhesive strength of an adhesive layer almost disappear. A Bernoulli chuck is moved close from the back side of the semiconductor wafer to separate the semiconductor wafer in a non-contact manner and to suspension-hold the semiconductor wafer in a state where the semiconductor wafer floats in the air.