Such a ground excavating apparatus that conducts excavation of a soft stratum by means of a bucket and employs an impact crusher for the excavation of such a hard stratum as a rock bed or the like is disclosed.Introduced in the present application is a ground excavator of such a category that comprises a housing, a bucket boom properly set in place in the said housing in a manner of being capable of traveling forward and rearward, a bucket properly fitted in place on the front end section of the said bucket boom in a manner of being capable of inclining, and an impact crushing mechanism well capable of traveling forward and rearward by virtue of a hydraulic jack housed in the said bucket boom, and employs the said bucket and the said impact crushing mechanism in an alternate manner to best suit the nature of the ground to be excavated.