An indexing apparatus for a rotary table has a support shaft rotatably supported by a base member in which indexed terminal positions of the rotary table is determined by abutment of a stopper member provided on the rotary table against positioning members provided on the base member. The indexing apparatus comprises a rack-pinion mechanism comprising a rack and a pinion fixed around the support shaft of the rotary table for rotating the same, a feed screw shaft rotatably supported by the base member and extending along the rack in a direction of the movement thereof, a breakable electric motor for driving the feed screw shaft, and a feed nut engaging the feed screw shaft. The rack and the feed nut are arranged so that either one of them has integral portions disposed at both sides of the other with spaces left on both the sides in the direction of the movement of the rack. Annular springs are disposed in each space. As the rotary indexing operation approaches the terminal position, the spring is elastically deformed in the direction of the movement of the rack so that shocks due to the abutting are prevented. Immediately before the indexed terminal positions, the speed of the motor is reduced and then the motor is braked.