A work machine, comprising: - a boom cylinder; - a first hydraulic pump that is capable of supplying hydraulic fluid to the boom cylinder through a boom primary spool; - an arm cylinder; - a second hydraulic pump that is capable of supplying hydraulic fluid to the arm cylinder through an arm secondary spool; - a third hydraulic pump that is capable of supplying hydraulic fluid to the arm cylinder through an arm primary spool; - a boom secondary spool that is capable of placing the boom cylinder in communication with the second hydraulic pump; - a pilot pressure sensor that detects an issuance of operating instructions to the boom cylinder and the arm cylinder, and - pump flow control means that is capable of adjusting the delivery flow rate of the first hydraulic pump, the delivery flow rate of the second hydraulic pump and the delivery flow rate of the third hydraulic pump on an individual basis in accordance with operation amounts designated by the operating instructions for the boom cylinder and the arm cylinder, the operating instructions being detected by the pilot pressure sensor; characterised in that, when a raising operation of the boom cylinder is independently performed, the pump flow control means adjusts the delivery flow rates of the first hydraulic pump and the third hydraulic pump such that both the first hydraulic pump and the third hydraulic pump supply hydraulic fluid to the boom cylinder, and when a raising operation of the boom cylinder and a crowding operation of the arm cylinder are performed in combination after a raising operation of the boom cylinder is independently performed, the second hydraulic pump and the third hydraulic pump each communicate with the arm cylinder and the pump flow control means increases a target flow rate to be supplied to the boom primary spool and decreases a target flow rate to be supplied to the boom secondary spool, and increases the delivery flow rate of the first hydraulic pump based on the increased target flow rate to be supplied to the boom primary spool and decreases the delivery flow rate of the second hydraulic pump based on the decreased target flow rate to be supplied to the boom secondary spool. - a boom cylinder; - a first hydraulic pump that is capable of supplying hydraulic fluid to the boom cylinder through a boom primary spool; - an arm cylinder; - a second hydraulic pump that is capable of supplying hydraulic fluid to the arm cylinder through an arm secondary spool; - a third hydraulic pump that is capable of supplying hydraulic fluid to the arm cylinder through an arm primary spool; - a boom secondary spool that is capable of placing the boom cylinder in communication with the second hydraulic pump; - a pilot pressure sensor that detects an issuance of operating instructions to the boom cylinder and the arm cylinder, and - pump flow control means that is capable of adjusting the delivery flow rate of the first hydraulic pump, the delivery flow rate of the second hydraulic pump and the delivery flow rate of the third hydraulic pump on an individual basis in accordance with operation amounts designated by the operating instructions for the boom cylinder and the arm cylinder, the operating instructions being detected by the pilot pressure sensor; characterised in that, when a raising operation of the boom cylinder is independently performed, the pump flow control means adjusts the delivery flow rates of the first hydraulic pump and the third hydraulic pump such that both the first hydraulic pump and the third hydraulic pump supply hydraulic fluid to the boom cylinder, and when a raising operation of the boom cylinder and a crowding operation of the arm cylinder are performed in combination after a raising operation of the boom cylinder is independently performed, the second hydraulic pump and the third hydraulic pump each communicate with the arm cylinder and the pump flow control means increases a target flow rate to be supplied to the boom primary spool and decreases a target flow rate to be supplied to the boom secondary spool, and increases the delivery flow rate of the first hydraulic pump based on the increased target flow rate to be supplied to the boom primary spool and decreases the delivery flow rate of the second hydraulic pump based on the decreased target flow rate to be supplied to the boom secondary spool.