This endoscope (1) has an observation optical system (3) that switches its observation mode between magnified observation and normal observation by moving some lenses in an optical-axis direction and a plurality of illumination optical systems (4A, 4C), wherein lens surfaces (4a, 4c) at the most distal ends of the plurality of illumination optical systems are disposed closer to a proximal end than a lens surface (3a) at the most distal end of the observation optical system (3), and all of the lens surfaces at the most distal ends of the plurality of illumination optical systems are disposed substantially parallel to the lens surface at the most distal end of the observation optical system, wherein the following conditional expressions (1) to (3) are satisfied. €ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ1.0 ‰¤ D_Back(far)/D_Back(near) < 3.0€ƒ€ƒ€ƒ€ƒ€ƒ(1) €ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ0.015 < D_Back(far)/D_far < 1.0€ƒ€ƒ€ƒ€ƒ€ƒ(2) €ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ1.01 < É(wide)/É(tele) < 5.0€ƒ€ƒ€ƒ€ƒ€ƒ(3)
