The invention provides a working unit control apparatus of an excavating and loading machine which can always judge a start of an excavation control at a proper timing. The working unit control apparatus has excavating state detecting means (43, 44) detecting an excavating state of a vehicle, and a controller (25) has a load judging portion (48) judging on the basis of a detecting amount, and automatic excavation control means (51) setting and outputting an automatic excavation command value to each of control valves on the basis of the judgement of said load judging portion, and an automatic excavation control is started when a boom lever is operated and it is judged that a vehicle is under excavation.