The invention provides an endoscope. The endoscope can make the light distribution performance of illumination light improved, a good observation view field is ensured, the top end part of the inserting part is miniaturized, and the insertability is improved. The endoscope comprises a tubular inserting part, a light guiding part, and a planoconcave lens, wherein the inserting part is provided witha top end part, the light guiding part is accommodated in the inserting part, and is used for guiding the illumination light to the top end part, the planoconcave lens is arranged at the top end partof the inserting part and is used for condensing light from the planoconcave lens and light from an observation area illuminated by the planoconcave lens, and the planoconcave lens is used for irradiating illumination light guided by the light guiding part; the end, opposite to the planoconcave lens, of the light guiding part extends in the direction approximately parallel to the optical axis ofan objective lens, and the shoulder of the top end part and the outer surface of the planoconcave lens located at the shoulder incline in the mode of converging to the top.