Abstract: An endoscope is provided that obtains a favorable field of view. The endoscope includes: an illumination optical system that has an illumination window protruding from an end surface of an insertion unit; a cylindrical body that protrudes from the end surface; and an observation window that is arranged inside the cylindrical body and protrudes from the end surface, in which the illumination window and the observation window satisfy Formulas (1) and (2), and an intersection between a straight line, which connects an edge of a light incident surface of the observation window and an edge of an end surface of the cylindrical body, and an optical axis of the illumination optical system is located to be closer to the insertion unit than the end surface of the insertion unit. C?D??(1) E?D??(2).

Abstract: An endoscope is provided which has a high insertability, that is, is easy to insert. The endoscope includes an insertion unit having a first area in which an attenuation rate of a repulsive force generated when bent is a positive value of 30% or lower. More preferably, the attenuation rate of the first area is 10% or higher and 30% or lower. The first area is in a range of 200 mm to 800 mm from a distal end side of the insertion unit.

Abstract: An endoscope is provided that obtains a favorable field of view. The endoscope includes: an illumination window that protrudes from an end surface of an insertion unit; an observation window that protrudes from the end surface; and an outlet that protrudes from the end surface and emits water or air to the observation window, and satisfies Formulas (1) and (2). C?D . . . (1) 2N?C . . . (2) C is a maximum protruding amount of the observation window the end surface of the insertion unit. D is a maximum protruding amount of the illumination window from the end surface of the insertion unit. N is a maximum protruding amount of an inner surface of the outlet from the end surface of the insertion unit.