To provide a range finder of amphibious camera, which can secure a sufficient accuracy as well in the air as underwater and permits small-sized construction of the whole device.

A projection lens 6 casts a ranging light onto an object to be photographed while a light receiving lens 2 receives the reflected light from the object 5, and a waterproof protector panel 1 is installed ahead of these lenses 6 and 2 in such an arrangement as not perpendicular to their optical axes. Because the light path differs in front of and beind the protector panel 1, depending upon its positioning, i.e., whether it lies underwater or in the air, an underwater projector element 13 and an aerial projector element 14 are installed behind the projection lens 6 where the mentioned difference in the light path is utilized, and also an underwater light receiver element 4a and an aerial light receiver element 4b are installed behind the light receiving lens.