A work machine comprising: a work device that has a plurality of front members including an arm; a plurality of hydraulic actuators (5, 6, 7) that include an arm cylinder driving the arm and that drive the plurality of front members; an operation device (45, 46) that gives instruction on operations of the plurality of hydraulic actuators (5, 6, 7) according to an operation of an operator; a controller having an actuator control section that controls at least one of the plurality of hydraulic actuators (5, 6, 7) according to velocities of the plurality of hydraulic actuators (5, 6, 7) and a predetermined condition when the operation device (45, 46) is operated; a posture sensor that senses a physical quantity concerning a posture of the arm; and an operation amount sensor that senses a physical quantity concerning an operation amount for the arm of operation amounts of the operation device (45, 46), characterized in that the controller includes: a first velocity calculation section that calculates a first velocity calculated from a sensed value from the operation amount sensor as a velocity of the arm cylinder; a second velocity calculation section that, based on a sensed value from the posture sensor, determines a direction of a load applied to the arm cylinder by the weight of the arm, and, upon determining that the direction of the load is opposite to a driving direction of the arm cylinder, calculates as the velocity of the arm cylinder a second velocity lower than the first velocity as a velocity of the arm cylinder; and a third velocity calculation section that, upon determining that the direction of the load is same as the driving direction of the arm cylinder, calculates as the velocity of the arm cylinder a third velocity equal to or higher than the first velocity as a velocity of the arm cylinder. a work device that has a plurality of front members including an arm; a plurality of hydraulic actuators (5, 6, 7) that include an arm cylinder driving the arm and that drive the plurality of front members; an operation device (45, 46) that gives instruction on operations of the plurality of hydraulic actuators (5, 6, 7) according to an operation of an operator; a controller having an actuator control section that controls at least one of the plurality of hydraulic actuators (5, 6, 7) according to velocities of the plurality of hydraulic actuators (5, 6, 7) and a predetermined condition when the operation device (45, 46) is operated; a posture sensor that senses a physical quantity concerning a posture of the arm; and an operation amount sensor that senses a physical quantity concerning an operation amount for the arm of operation amounts of the operation device (45, 46), characterized in that the controller includes: a first velocity calculation section that calculates a first velocity calculated from a sensed value from the operation amount sensor as a velocity of the arm cylinder; a second velocity calculation section that, based on a sensed value from the posture sensor, determines a direction of a load applied to the arm cylinder by the weight of the arm, and, upon determining that the direction of the load is opposite to a driving direction of the arm cylinder, calculates as the velocity of the arm cylinder a second velocity lower than the first velocity as a velocity of the arm cylinder; and a third velocity calculation section that, upon determining that the direction of the load is same as the driving direction of the arm cylinder, calculates as the velocity of the arm cylinder a third velocity equal to or higher than the first velocity as a velocity of the arm cylinder. a first velocity calculation section that calculates a first velocity calculated from a sensed value from the operation amount sensor as a velocity of the arm cylinder; a second velocity calculation section that, based on a sensed value from the posture sensor, determines a direction of a load applied to the arm cylinder by the weight of the arm, and, upon determining that the direction of the load is opposite to a driving direction of the arm cylinder, calculates as the velocity of the arm cylinder a second velocity lower than the first velocity as a velocity of the arm cylinder; and a third velocity calculation section that, upon determining that the direction of the load is same as the driving direction of the arm cylinder, calculates as the velocity of the arm cylinder a third velocity equal to or higher than the first velocity as a velocity of the arm cylinder.