Separating method, separating apparatus, and separating system

A separating method, comprising:

• holding a combined substrate in which a first substrate and a second substrate are bonded;
• and
• separating the first substrate from the combined substrate, starting from a side surface of the combined substrate,
• wherein the separating of the first substrate comprises:
• bringing a fluid containing water into contact with the side surface;
• supplying the fluid containing water to the side surface from a nozzle;
• and
• pressing a blade firmly against the side surface to which the fluid containing water is supplied by moving the blade in a horizontal direction,
• wherein the fluid containing water is a liquid, and
• the separating of the first substrate is performed by immersing the combined substrate in the fluid containing water, the fluid being stored.