A control device is provided with: a posture information storage unit that stores posture associated information associated with workability being an evaluation criterion at a time of a posture for each piece of posture information of an operator; a posture information detection unit that acquires posture information of the operator during work as current posture information; a posture information calculation unit that obtains, from the posture associated information, ideal posture information for making improvement on workability of the current posture information, obtained by referring to the posture associated information in the storage unit from the current posture information; and a posture information notification unit that notifies the ideal posture information obtained by the calculation unit as an improvement proposal.