An operation support device includes an operation part in which the operation input is performed by an operator, an action part to which a surgical tool is attached and which is driven by the operation input, a drive source that is provided in the operation part, and generates a driving force which adjusts the manipulation resistance at the time of the operation input, and a control unit that sets the magnitude and direction of the driving force, wherein the control unit sets the magnitude and direction of the driving force based on the operation input to the operation part.