An endoscope device comprising: an imaging optical system including an objective lens disposed at a distal end part of an endoscope and having an optical axis (Ax); an imaging element adapted to image a subject through the imaging optical system; a signal processing unit adapted to process a captured image signal obtained by imaging the subject by the imaging element to generate a captured image; an auxiliary measurement light emitting unit adapted to emit planar auxiliary measurement light forming a plane into a visual field of the imaging optical system from the distal end part said plane intersecting the optical axis (Ax) at a certain position in the optical axis direction; and a display control unit adapted to cause a display unit to display the captured image including an intersection line between the auxiliary measurement light and the subject that is formed in a portion where the plane formed by the auxiliary measurement light intersects the subject, the intersection line changing in the position thereof in a vertical direction as the distance to the subject on which the intersection line is formed changes; wherein the display control unit is adapted to cause a scale serving as an index of a size of the subject to be displayed on the intersection line included in the captured image, the scale being caused based on a prestored data table showing a relationship between positions in said vertical direction and actual sizes of the image per pixel at the positions, and wherein the display control unit is adapted to add information indicating an effective visual field determined in advance in the visual field of the imaging optical system to the captured image to display the information, the effective visual field being a range suitable for displaying the scale. an imaging optical system including an objective lens disposed at a distal end part of an endoscope and having an optical axis (Ax); an imaging element adapted to image a subject through the imaging optical system; a signal processing unit adapted to process a captured image signal obtained by imaging the subject by the imaging element to generate a captured image; an auxiliary measurement light emitting unit adapted to emit planar auxiliary measurement light forming a plane into a visual field of the imaging optical system from the distal end part said plane intersecting the optical axis (Ax) at a certain position in the optical axis direction; and a display control unit adapted to cause a display unit to display the captured image including an intersection line between the auxiliary measurement light and the subject that is formed in a portion where the plane formed by the auxiliary measurement light intersects the subject, the intersection line changing in the position thereof in a vertical direction as the distance to the subject on which the intersection line is formed changes; wherein the display control unit is adapted to cause a scale serving as an index of a size of the subject to be displayed on the intersection line included in the captured image, the scale being caused based on a prestored data table showing a relationship between positions in said vertical direction and actual sizes of the image per pixel at the positions, and wherein the display control unit is adapted to add information indicating an effective visual field determined in advance in the visual field of the imaging optical system to the captured image to display the information, the effective visual field being a range suitable for displaying the scale.