A fixing device for an endoscope that allows easy detachment of the endoscope from an endoscope holder even with the endoscope kept inserted in a body cavity is provided.A fixing device for fixing an endoscope capable of observing an operative site in a body cavity using an endoscope having an insertion portion to be inserted into the body cavity and an endoscope body attached at an end of the insertion portion. The fixing device includes a holder body which is attached to a fixing stand placed on a floor and holds the endoscope body in a rotatable manner. The holder body includes a detaching mechanism that allows the endoscope body to be detached from the holder body while keeping the insertion portion inserted in the body cavity.
