PROBLEM TO BE SOLVED: To provide a posture controller of a work machine which can control tillage depth in a region where the elevating speed of a hydraulic pressure elevating cylinder 71 is slow and prevent hunting.SOLUTION: In a posture controller of a work machine which mounts in an elevating manner a ground work machine 24 via a link mechanism 23 on a work vehicle 1 supported by front wheels 3 and rear wheels 4 so as to be able to freely travel, and includes a hydraulic pressure elevating cylinder 71 and an elevation valve 81 which vertically move the ground work machine 24 and a sensor wire 111 which detects the a ground work sensor 43 angle of the ground work machine 24, a sensor input regulation body 112 is provided on the midway of connection of the elevation valve 81 and the sensor wire 111.
