To provide a controller of a work machine capable of vertically lifting an attachment for work independent of a length of a boom or an arm.

When an inclination angle of an excavation rod to a vertical direction exceeds a prescribed threshold at the front of a revolving superstructure, control of pulling the arm is executed on the basis of actuator drive control means (steps 1-2). Also, when the inclination angle of the excavation rod to the vertical direction exceeds the prescribed threshold at the back of the revolving superstructure, control of pushing the arm is executed on the basis of the actuator drive control means (steps 3-4).