An endoscope apparatus capable of observing both 2D observation and 3D observation satisfactorily. The endoscope apparatus 1 having the function of switching between 2D observation for plan view and 3D observation for stereoscopic viewing has an image processing section 4 for reducing the distortion of the imaging optical system at the time of 3D observation and the image processing section 4 Is an endoscope apparatus which performs image processing satisfying the following conditional expression (1). 0.1