A fitting device for fitting a fitting workpiece, which is held by a robot, to a workpiece to be fitted by force control, comprises: a force detecting portion for detecting a force and moment acting on a control point of the fitting workpiece; a judging portion for judging whether or not clogging is caused between the fitting workpiece and the workpiece to be fitted at the time of fitting; and a changing portion for changing a position of the control point according to a distance by which the fitting workpiece enters the workpiece to be fitted and for pressing the fitting workpiece against the workpiece to be fitted in a direction perpendicular to the fitting direction so as to adjust a posture of the fitting workpiece on the basis of the control point that has been changed, in the case where it is judged by the judging portion that clogging is caused. Due to the foregoing, posture of the fitting workpiece can be appropriately adjusted in a short period of time so that the fitting workpiece can be fitted into the workpiece to be fitted.