A motor control device (26, 75, 86) configured to control a motor (21, 71, 81) depending on a position of a rotation detection object, the motor being a dynamic force source, the rotation detection object rotating while interlocking with the motor, the motor and the rotation detection object being included in a mechanical apparatus, the mechanical apparatus including a plurality of constituent elements that interlock with each other, the motor control device comprising: a computation circuit (31, 75a, 86a) configured to compute an absolute rotation angle of the rotation detection object, using a relative rotation angle of a first constituent element of the mechanical apparatus and a rotation number conversion value, the relative rotation angle of the first constituent element being detected through a relative angle sensor (24, 73, 84) that is provided in the mechanical apparatus, the rotation number conversion value being a value resulting from converting an absolute rotation angle of a second constituent element of the mechanical apparatus into a rotation number of the first constituent element, the absolute rotation angle of the second constituent element being detected through an absolute angle sensor (25a, 74a, 85a) that is provided in the mechanical apparatus, characterized in that the computation circuit (31, 75a, 86a) includes a correction processing unit configured to correct the rotation number conversion value, based on comparison between the relative rotation angle of the first constituent element and a rotation angle conversion value, on a premise that a difference between the relative rotation angle of the first constituent element and the rotation angle conversion value is within a rotation angle equivalent to half rotation of the first constituent element and that the relative rotation angle of the first constituent element is correct, the rotation angle conversion value being a value resulting from converting a rotation angle correspondence value into the relative rotation angle of the first constituent element, the rotation angle correspondence value corresponding to the relative rotation angle of the first constituent element that is obtained when the rotation number conversion value is evaluated. a computation circuit (31, 75a, 86a) configured to compute an absolute rotation angle of the rotation detection object, using a relative rotation angle of a first constituent element of the mechanical apparatus and a rotation number conversion value, the relative rotation angle of the first constituent element being detected through a relative angle sensor (24, 73, 84) that is provided in the mechanical apparatus, the rotation number conversion value being a value resulting from converting an absolute rotation angle of a second constituent element of the mechanical apparatus into a rotation number of the first constituent element, the absolute rotation angle of the second constituent element being detected through an absolute angle sensor (25a, 74a, 85a) that is provided in the mechanical apparatus, characterized in that the computation circuit (31, 75a, 86a) includes a correction processing unit configured to correct the rotation number conversion value, based on comparison between the relative rotation angle of the first constituent element and a rotation angle conversion value, on a premise that a difference between the relative rotation angle of the first constituent element and the rotation angle conversion value is within a rotation angle equivalent to half rotation of the first constituent element and that the relative rotation angle of the first constituent element is correct, the rotation angle conversion value being a value resulting from converting a rotation angle correspondence value into the relative rotation angle of the first constituent element, the rotation angle correspondence value corresponding to the relative rotation angle of the first constituent element that is obtained when the rotation number conversion value is evaluated.