WORK MACHINE

A property calculation section of the controller calculates a horizontal distance between a boom proximal end portion and an arm distal end portion based on a detection signal input from an attitude detector, calculates a weight of the distal end attachment based on the horizontal distance and a detection signal input from a holding pressure detector in a state where a distal end attachment is disposed at a pressure release position, and calculates a gravity center position of the distal end attachment based on the weight of the distal end attachment, a detection signal input from the holding pressure detector, and a detection signal input from the attitude detector in a state where the distal end attachment is disposed at a displacement position that is a position different from the pressure release position.