An endoscope including an operation part having a forceps entrance, a distal end part having a flat end surface, an observation window base part formed on the flat end surface of the distal end part so as to protrude distally from the flat end surface, an observation window disposed on the observation window base part, and a forceps exit disposed on the distal end part, a forceps being inserted through a forceps entrance protruding from the forceps exit. The observation window base part has a flat surface, and an outer peripheral shape of the observation window base part is inclined and connects the flat end surface of the distal end part with the flat surface of the observation window base part.
