A separating device for separating an electronic main body from a substrate bonded thereto comprises a platform, a conveying section, a dissolving section, a cleaning section, and a first partition plate. The conveying section is disposed on the platform for moving the electronic main body and the substrate forward. The dissolving section is disposed on the platform for spraying a solvent onto the bonded electronic main body and substrate. The cleaning section is also disposed on the platform for cleaning the electronic main body. The first partition plate is located between the dissolving section and the cleaning section and has at least one first slot, which allows only the electronic main body but not the substrate to pass therethrough, so that the electronic main body is separated from the substrate at the first partition plate. A method for separating the electronic main body and the substrate is also provided.