A construction machine (15, Fig.2) comprising: a body (9, 10); work equipment provided on the body (9, 10), having a plurality of swingable work elements (8, 11, 12); a plurality of hydraulic actuators (5, 6, 7) for driving the work equipment; a plurality of ground angle sensors (13a to 13d) for detecting ground angles of the work elements (8, 11, 12); and an excavation support device including an information processing device for generating information to support excavation work of an operator, characterized in that wherein the information processing device includes: a load information acquiring section for acquiring load information including a load direction in a swing center of at least one of the work elements according to signals from the ground angle sensors (13a to 13d); and a working point position calculating section for calculating a position of a working point of the work equipment according to the signals from the ground angle sensors (13a to 13d) and the load information acquired by the load information acquiring section according to the signals from the ground angle sensors (13a to 13d); and an angle calculating section for calculating the ground angle of each of the work elements according to the signals from the ground angle sensors (13a to 13d); and a dimension setting section for setting dimension information of each of the work elements by calculation according to a measured value entered from outside, the signals from the ground angle sensors (13a to 13d), and the load information from the load information acquiring section; and the working point position calculating section calculates the position of the working point of the work equipment according to not only the load information from the load information acquiring section but also the dimension information set by the dimension setting section, and the ground angle calculated by the angle calculating section. wherein the information processing device includes: a load information acquiring section for acquiring load information including a load direction in a swing center of at least one of the work elements according to signals from the ground angle sensors (13a to 13d); and a working point position calculating section for calculating a position of a working point of the work equipment according to the signals from the ground angle sensors (13a to 13d) and the load information acquired by the load information acquiring section according to the signals from the ground angle sensors (13a to 13d); and a load information acquiring section for acquiring load information including a load direction in a swing center of at least one of the work elements according to signals from the ground angle sensors (13a to 13d); and a working point position calculating section for calculating a position of a working point of the work equipment according to the signals from the ground angle sensors (13a to 13d) and the load information acquired by the load information acquiring section according to the signals from the ground angle sensors (13a to 13d); and an angle calculating section for calculating the ground angle of each of the work elements according to the signals from the ground angle sensors (13a to 13d); and a dimension setting section for setting dimension information of each of the work elements by calculation according to a measured value entered from outside, the signals from the ground angle sensors (13a to 13d), and the load information from the load information acquiring section; and the working point position calculating section calculates the position of the working point of the work equipment according to not only the load information from the load information acquiring section but also the dimension information set by the dimension setting section, and the ground angle calculated by the angle calculating section.