To prevent protrusion of a wire by accumulation of dust and trouble such as rough winding to a drum by housing a wire winding drum for installing a case enclosing an upper/lower limit switch mechanism of a measuring weight and two fixed wire guide rollers for installing a detecting encoder in a single box.

A case 10 enclosing a detecting switch 8 and an upper/lower limit switch 9 is installed on a wire winding drum 1 for unwinding/winding a wire for suspending a measuring weight. A level detecting encoder 4 is arranged on a fixed guide roller 3. This pile head level gauge is constituted by arranging these in a box 5. Thus, a structure is simplified, and since these members are housed in a single box, trouble by accumulation of dust can be solved, and since the detecting encoder 4 is installed on the fixed guide roller 3, even if rough winding is caused, an accurate level can be detected.