The present invention relates to a lithographic apparatus including an illumination system configured to condition a beam of radiation, a support structure configured to support a patterning device, the patterning device configured to pattern the beam of radiation, a substrate table configured to hold a substrate, a projection system configured to project the patterned beam onto a target portion of the substrate, and a robot configured to exchange the exchangeable object. The robot includes a base part and a movable part, the movable part being moveably connected to the base part and including an object handler configured to handle the exchangeable object. The apparatus further includes an object detector configured to detect the exchangeable object in the object handler, the object detector including a transmitter configured to transmit a signal and a receiver configured to receive a signal, the transmitter and the receiver being positioned separately from the movable part of the robot.