Image dimension measuring device

Expediency is improved in that it is made possible for an imaging region to record an image of a measuring element without a user setting an angle of rotation of a measuring object. A control unit identifies a reference rotation angle when measuring and, based on a relative rotation angle stored in advance with respect to the reference rotation angle, calculates a measurement angle to measure a measurement element. The control unit controls a rotating unit such that a rotating angle of the rotating unit becomes the measurement angle. The control unit performs a process of measuring a dimension of the measuring element based on a measurement object image captured by an imaging area when the rotation angle of the rotation unit becomes the measurement angle.