Abstract: In greasing operation for pin-connected parts of a work machine, a swivel bearing, and the like of a construction machine, particularly a hydraulic excavating machine which has a number of parts which require greasing at a short greasing interval, automatic greasing is carried out when a total of added values of operation time of greased parts, such as the pin-connected parts of the work machine and the swivel bearing, or operation time and short non-operation time regarded as operation time reaches a specified greasing interval, and is stopped upon completion of greasing operation, so as to save operator's efforts in greasing work which requires a lot of man-hours and simultaneously prevent contamination of the periphery of the excavating machine with excessive grease overflowing from respective greased parts.