An optical disk apparatus is provided, in which the optical disk tray can slide smoothly in and out, and the insertion and removal of an optical disk is facilitated, and wherein inadvertent scratches are not produced on the optical disk surface, and flying pieces of optical disk damaged during rotation are completely prevented from exiting the apparatus. That supply rail is formed of first segments located on a first metallization level and second segments located on a second metallization level with at least one conductor element extending between the first and second segments to electrically connect successive segments of the supply rail. The choke plate has a peripheral choke channel which prevents leakage of microwave energy between the launch box and choke plate, enabling the choke plate and match plate to be bolted to the wall.