In a trace generation device including a trace generation determination unit that outputs a command of trace generation, when a difference of an actual load applied to a bucket and a reference load is equal to or larger than a predetermined value during excavation and a candidate trace generation unit that generates a trace in which a work amount is almost constant, after the command is output, the reference load is an estimated load and the command of the trace generation is output when the difference of the actual load and the estimated load is equal to or larger than the predetermined value during the excavation. As a result, working efficiency can be raised while a trace in which an excavation amount is almost constant is generated.