PURPOSE: To promote the cost down in the whole production line and improve its work efficiency, by providing track rails, which hold both sides of a substrate positioning the substrate, on a rotary table loading the substrate in a printed substrate positioning mechanism in an electronic parts mounting device.

CONSTITUTION: A device provides on a supporting bed 3 track rails 37, 38, for holding both sides of a substrate 36 and driving it to be fed further positioning the substrate, on rotary tables 18, 19 loading the substrate 36 to be held. Accordingly, the device arranges, for instance, a substrate storage magazine, having many short track rails continuously connectable with these track rails 37, 38 in opposed surfaces of the internal walls of said rails 37, 38 further holding the many substrates 36 to be laminated in a predetermined distance by the short track rails, in the upstream and the downstream sides of the track rails 37, 38, further the device provides a substrate storage magazine elevator mechanism and a substrate moving means comprising, for instance, air cylinders 29, 42, 49 moving in one direction the substrate 36 placed between the track rails 37, 38 and the short track rails.In this way, the device carries the substrate 36 into and out of the rotary tables 18, 19.