To provide a height measuring device for industrial machine which can measure the height position of the base-side end of the bucket of a power shovel with a simple constitution.

A liquid-pressure pipe 20 filled in with silicone oil is provided so as to connect the front end and base-side end of the height adjusting mechanism 124 (a boom 106 and an arm 108) of a power shovel 100 to each other. When the pipe 20 is provided, one end of the pipe 20 is constituted as a closed end by connecting the end to a liquid-pressure sensor unit 18 and the other end is constituted as an opened end opened to the atmospheric pressure by connecting the end to a tank 16. Then the liquid pressure in the pipe 20 is detected by means of the sensor chip of the sensor unit 18. Therefore, the height difference (h) between the liquid level in the tank 16 and the sensor chip can be measured directly.