The endoscope has a window made of a transparent material and closing an opening at a distal end of a shaft in fluid-tight manner. Swingable prisms (41, 42) are provided at the distal end of the shaft for adjustable deflection of light on a lens (52), where the light falls in the shaft through the window. The prisms are made of mono-crystalline diamond by chemical vapor deposition, and anti-reflection coatings are arranged on light inlet and outlet surfaces of the prisms, where distance between a reflecting base surface and a top surface of the prisms amounts to 2.5 to 3.5 mm.
