Abstract: A single automatic part insertion machine which can insert the leads of various electronic components such as resistors, IC chips, IF transformers, variable resistors, connectors and so on, into specified insertion or mounting holes of printed circuit boards. The boards are supported on a common set of conveyor rails in one row, and are displaced in X and Y coordinate directions while they are transferred from a feeding position to an unloading position. Specified lead insertion holes of specified printed circuit boards are thus aligned one at a time with selected units of a number of parts feeding means in a predetermined sequence, so that the leads of corresponding electronic components may be inserted into specified insertion holes of the printed circuit boards and clinched if required. An automatic unfinished printed circuit board loading device is provided, as well as an automatic finished printed circuit board stacking device.