The present invention provides an automatic assembling machine (100) for assembling an electron component (180) for a base plate. The automatic assembling machine comprises a conveying system (130) for conveying the base plate to and out of an assembly region (135), the first gantry mounting system (110) for positioning and moving the first assembling head (112) at least between the first element pick-up region (114) and the assembly region (135), the second gantry mounting system (120) for positioning and moving the second assembling head (122) at least between the second element pick-up region (124) and the assembly region (135), and an isolation device (154) that can be inserted at an isolation position in the automatic assembling machine. Thereby, when the isolation device is inserted, he first element pick-up region and the assembling region are separated in space, namely, when an operator (190) only performs manual operations in the first element pick-up region, the second gantry mounting system can continued to be put into service. The present invention provides a manual operation executing method in the automatic assembling machine (100) and the automatic assembling machine having a control device for executing the method.