An operation support device supports input operations on a coordinate input device configured to detect change in electrostatic capacitance. The operation support device includes a main shaft support member placed on the coordinate input device, an operation member, a support plate, a first rotating plate, and a first member. When, in conjunction with the operation member, a state in which the support plate and the first rotating plate make contact with each other changes to a state in which the support plate and the first rotating plate are separated from each other, difference between a distance from an end portion of the first member to the coordinate input device and a distance from a detection end portion of the second member to the coordinate input device decreases.