A surgical microscope device comprising: a microscope unit (110, 701, 801) configured to image an operative site of a patient on an operating table, and output an image signal; and a support unit (120, 703, 803) configured to support the microscope unit at a distal end, wherein the support unit includes a first arm (290a, 707a, 807a), a second arm (290b, 707b, 807b) and a prop unit (290c, 707c, 807c) in an order from a distal-end side, the second arm supporting a proximal end of the first arm at a distal end rotatably around a first rotation axis orthogonal to a vertical direction, the vertical direction being a direction vertical to the floor, and a front-back direction, the front-back direction being a direction orthogonal to the vertical direction, the prop unit extending from the floor substantially in the vertical direction and supporting a proximal end of the second arm at a distal end rotatably around a second rotation axis orthogonal to the vertical direction and the front-back direction, the support unit is configured such that a length of the second arm (290b, 707b, 807b) as a length between the first rotation axis and the second rotation axis is greater than a length of the first arm (290a, 707a, 807a) as a length between the first rotation axis and an optical axis of the microscope unit (110, 701, 801) disposed to have the optical axis substantially vertical, and in a case where the first arm is configured parallel to the floor, the length of the second arm (290b, 707b, 807b) is represented as V, a maximum value of a rotation angle of the second arm (290b, 707b, 807b) with the prop unit is represented as r 2max wherein the rotation angle is zero when the second arm extends upwards in the vertical direction, a height of an objective lens of the microscope unit (110, 701, 801) from the floor in an operation at a standing position of a surgeon is represented as Z 1, and a height of the objective lens of the microscope unit (110, 701, 801) from the floor in an operation at a seated position of the surgeon is represented as Z 2, the length V, the maximum value r 2max of the rotation angle, the height Z 1, and the height Z 2 satisfy a relationship represented as Z 1 - Z 2 < V(1 - cos(r 2max)). a microscope unit (110, 701, 801) configured to image an operative site of a patient on an operating table, and output an image signal; and a support unit (120, 703, 803) configured to support the microscope unit at a distal end, wherein the support unit includes a first arm (290a, 707a, 807a), a second arm (290b, 707b, 807b) and a prop unit (290c, 707c, 807c) in an order from a distal-end side, the second arm supporting a proximal end of the first arm at a distal end rotatably around a first rotation axis orthogonal to a vertical direction, the vertical direction being a direction vertical to the floor, and a front-back direction, the front-back direction being a direction orthogonal to the vertical direction, the prop unit extending from the floor substantially in the vertical direction and supporting a proximal end of the second arm at a distal end rotatably around a second rotation axis orthogonal to the vertical direction and the front-back direction, the support unit is configured such that a length of the second arm (290b, 707b, 807b) as a length between the first rotation axis and the second rotation axis is greater than a length of the first arm (290a, 707a, 807a) as a length between the first rotation axis and an optical axis of the microscope unit (110, 701, 801) disposed to have the optical axis substantially vertical, and in a case where the first arm is configured parallel to the floor, the length of the second arm (290b, 707b, 807b) is represented as V, a maximum value of a rotation angle of the second arm (290b, 707b, 807b) with the prop unit is represented as r 2max wherein the rotation angle is zero when the second arm extends upwards in the vertical direction, a height of an objective lens of the microscope unit (110, 701, 801) from the floor in an operation at a standing position of a surgeon is represented as Z 1, and a height of the objective lens of the microscope unit (110, 701, 801) from the floor in an operation at a seated position of the surgeon is represented as Z 2, the length V, the maximum value r 2max of the rotation angle, the height Z 1, and the height Z 2 satisfy a relationship represented as Z 1 - Z 2 < V(1 - cos(r 2max)).