A controller includes a storage unit that stores a map in which an operation amount and an upper limit value of suction torque of a hydraulic pump are associated with each other, for each operation content identified by a cylinder that is an operation object out of the cylinders, and by a direction of operation performed on this cylinder; an operation torque determination unit that determines the upper limit value of suction torque for each cylinder by using the map stored in the storage unit when an actuation command relating to at least one cylinder is input by an operation lever; a high-level selection unit that selects the maximum upper limit value of suction torque out of the upper limit values of suction torque determined by the operation torque determination unit; and a regulator that regulates a displacement of the hydraulic pump so as to obtain torque equal to or lower than the suction torque selected by the high-level selection unit.