An endoscope apparatus measuring a subject using a pattern projection image of the subject on which a light and dark pattern of light is projected, includes an insertion tube； an image sensor； an objective optical system forming the subject image on the image sensor； an illumination light source illuminating the subject； a pattern projector projecting the light and dark pattern onto the subject； and a projection window disposed at a distal end portion of the insertion tube. When the projection window is viewed from the front and the distal end portion of the insertion tube is divided into two sides by an imaginary first plane which includes a central axis of the insertion tube, a center of the projection window is at one of the two sides of the distal end portion of the insertion tube. An observation window is disposed at the distal end portion of the insertion tube. When the projection window is viewed from the front, a center of the observation window is disposed at the other of the two sides of the distal end portion of the insertion tube.
