A robot cleaner includes a main body, a light transmitting unit, an image sensor, a base, a rotation drive unit, and an elevation drive unit. The light transmitting unit emits light. The light reflected or scattered by an obstacle is sensed by the image sensor. The base supports the light transmitting unit and the image sensor and is rotatably and vertically movably disposed in the main body. The rotation drive unit rotates the base. The elevation drive unit allows the base to retract or protract from the main body.