To adjust the attitude of a camera platform to a proper position horizontally and vertically, and easily adjust the attitude of it in accordance with action of the subject.

In this leg device, the camera platform 7 is installed on leg bodies 1 through a ball joint 4 comprising a protruded ball part 41 and a protruded ball receiving part 42 rotatably engaged with the protruded ball part 41. In the protruded ball part 41, annular grooves 43, and curved grooves 44 crossing the annular grooves 42 at a plurality of positions are provided. The protruded ball receiving part 42 is provided with engagement protrusions 45 that can be engaged with the annular grooves 43 and the curved grooves 44. As the engagement protrusions 45 are engaged with the annular grooves 43 or the curved grooves 44, the camera platform is rotated straight horizontally and vertically.