PROBLEM TO BE SOLVED: To provide a focus control device of an endoscope device, an endoscope device, a focus control method of an endoscope device, etc. capable of automatically starting autofocus control in an enlarged observation state.SOLUTION: A focus control device includes: an image acquisition unit for acquiring an image captured by an image capturing optical system having at least a screening observation state and a close magnification observation state an evaluation value calculation unit for calculating a contrast value in a predetermined region of the captured image for evaluating a focus state of a subject image based on the captured image a determination information calculation unit for calculating a contrast variation amount indicating a temporal variation in the contrast value based on the contrast value a determination unit 360 for determining whether the observation state is the screening observation state or the close magnification observation state based on the contrast variation amount and a focus control unit 365 for starting or ending the autofocus control based on the result of the determination.SELECTED DRAWING: Figure 8
