A construction machine comprising: a hydraulic pump that is of bidirectional delivery type and bidirectional variable displacement type, and has a first port and a second port; a hydraulic cylinder that has a first hydraulic working oil chamber and a second hydraulic working oil chamber, and performs a pulling action in a case of discharge of hydraulic working oil from the first hydraulic working oil chamber, and a pushing action in the case of discharge of hydraulic working oil from the second hydraulic working oil chamber; a first flow path that connects the first port of the hydraulic pump and the first hydraulic working oil chamber of the hydraulic cylinder; a second flow path that connects the second port of the hydraulic pump and the second hydraulic working oil chamber of the hydraulic cylinder; a discharge flow path (13, 16) branched from the first flow path; a discharge valve that is disposed in the discharge flow path, and controls a flow rate of hydraulic working oil discharged from the first hydraulic working oil chamber of the hydraulic cylinder to the discharge flow path; an operation device that issues an instruction for an action of the hydraulic cylinder; and a controller (56, 56A, 56B) that controls the hydraulic pump and the discharge valve on a basis of the instruction of the operation device (549, characterized in that the controller (56, 56A, 56B) controls the hydraulic pump and the discharge valve such that at least a part of hydraulic working oil discharged from the first hydraulic working oil chamber of the hydraulic cylinder is discharged to the discharge flow path in accordance with an operation amount of the operation device when the operation amount of the operation device lies within a fine operation region during the pulling action of the hydraulic cylinder in a state that an external load is applied in a contraction direction of the hydraulic cylinder. a hydraulic pump that is of bidirectional delivery type and bidirectional variable displacement type, and has a first port and a second port; a hydraulic cylinder that has a first hydraulic working oil chamber and a second hydraulic working oil chamber, and performs a pulling action in a case of discharge of hydraulic working oil from the first hydraulic working oil chamber, and a pushing action in the case of discharge of hydraulic working oil from the second hydraulic working oil chamber; a first flow path that connects the first port of the hydraulic pump and the first hydraulic working oil chamber of the hydraulic cylinder; a second flow path that connects the second port of the hydraulic pump and the second hydraulic working oil chamber of the hydraulic cylinder; a discharge flow path (13, 16) branched from the first flow path; a discharge valve that is disposed in the discharge flow path, and controls a flow rate of hydraulic working oil discharged from the first hydraulic working oil chamber of the hydraulic cylinder to the discharge flow path; an operation device that issues an instruction for an action of the hydraulic cylinder; and a controller (56, 56A, 56B) that controls the hydraulic pump and the discharge valve on a basis of the instruction of the operation device (549, characterized in that the controller (56, 56A, 56B) controls the hydraulic pump and the discharge valve such that at least a part of hydraulic working oil discharged from the first hydraulic working oil chamber of the hydraulic cylinder is discharged to the discharge flow path in accordance with an operation amount of the operation device when the operation amount of the operation device lies within a fine operation region during the pulling action of the hydraulic cylinder in a state that an external load is applied in a contraction direction of the hydraulic cylinder.