CONSTRUCTION MACHINE

A hydraulic excavator includes a lower travelling body, an upper slewing body, a sensor which detects presence/absence of an obstacle in a monitoring region set around the hydraulic excavator in advance and a distance to the obstacle, a control unit which calculates first position information including positional coordinates of an obstacle relative to a reference position set in advance in the hydraulic excavator on the basis of a detection result obtained by the sensor, a time counting unit which acquires time information including time when an obstacle is detected, and a storage unit which stores log data correlating the first position information with the time information.