A construction machine comprising: a multi-joint work implement assembly configured by connecting a plurality of driven members (1a, 1b, 1c) that can each rotate about a rotating shaft provided on a joint; a plurality of hydraulic actuators (3a, 3b, 3c) each adapted to drive one of the plurality of driven members to rotate about the rotating shaft; a plurality of operating units (4a, 4b, 4c) each adapted to give a motion instruction to one of the plurality of hydraulic actuators in accordance with a operation amount thereof; a plurality of flow control valves (5a, 5b, 5c) each driven in response to an operation signal output in accordance with the operation amount of one of the plurality of operating units to control a flow rate and a flow direction of a hydraulic fluid supplied to one of the plurality of hydraulic actuators; and a control unit configured to execute an area limiting control which controls at least one of a driving direction and a driving speed of at least one of the plurality of hydraulic actuators based on the operation amount of each of the plurality of operating units and a posture and a position of each of the driven members such that the closer a distance from a boundary of a set area within which a tip portion of the work implement assembly can move, to the tip portion gets to zero, the closer a speed vector component of the tip portion perpendicular to the boundary gets to zero, characterized in that the construction machine comprises a first sensor group (8a, 8b, 8c) consisting of a plurality of sensors for detecting rotation angles of the plurality of driven members relative to the respective rotating shafts, respectively; and a second sensor group (81a, 81b, 81c) consisting of a plurality of sensors for detecting tilting angles of the plurality of driven members relative to a reference plane, respectively, the control unit configured to select, during execution of the area limiting control, from among the first sensor group and the second sensor group, a sensor to use for calculating a posture and a position of each of the plurality of driven members, in accordance with a magnitude of speed of at least one of the plurality of driven members. a multi-joint work implement assembly configured by connecting a plurality of driven members (1a, 1b, 1c) that can each rotate about a rotating shaft provided on a joint; a plurality of hydraulic actuators (3a, 3b, 3c) each adapted to drive one of the plurality of driven members to rotate about the rotating shaft; a plurality of operating units (4a, 4b, 4c) each adapted to give a motion instruction to one of the plurality of hydraulic actuators in accordance with a operation amount thereof; a plurality of flow control valves (5a, 5b, 5c) each driven in response to an operation signal output in accordance with the operation amount of one of the plurality of operating units to control a flow rate and a flow direction of a hydraulic fluid supplied to one of the plurality of hydraulic actuators; and a control unit configured to execute an area limiting control which controls at least one of a driving direction and a driving speed of at least one of the plurality of hydraulic actuators based on the operation amount of each of the plurality of operating units and a posture and a position of each of the driven members such that the closer a distance from a boundary of a set area within which a tip portion of the work implement assembly can move, to the tip portion gets to zero, the closer a speed vector component of the tip portion perpendicular to the boundary gets to zero, characterized in that the construction machine comprises a first sensor group (8a, 8b, 8c) consisting of a plurality of sensors for detecting rotation angles of the plurality of driven members relative to the respective rotating shafts, respectively; and a second sensor group (81a, 81b, 81c) consisting of a plurality of sensors for detecting tilting angles of the plurality of driven members relative to a reference plane, respectively, the control unit configured to select, during execution of the area limiting control, from among the first sensor group and the second sensor group, a sensor to use for calculating a posture and a position of each of the plurality of driven members, in accordance with a magnitude of speed of at least one of the plurality of driven members.