To provide a product having a leg capable of folding in which the work of rotating the leg to the standing position or the folding position can be done easily, and an installation method for the leg of the product.

The leg 13 is fitted to the leg installation part 15 at four corners of the support frame 12 of a portable foot warmer of a lattice wooden frame 11 by a leg installation fitting 14. In the leg installation fitting 14, a lower installation unit 19 and an upper installation unit 20 are linked by a support axle 21. A cylindrical unit 25 is provided between the lower installation unit 19 and the upper installation unit 20, and a compression spring 26 is housed in the cylindrical unit 25. When the leg 13 is rotated, the compression spring 26 is compressed, and by the repulsive force of the compression spring 26, the leg 13 is energized in the direction of rotating to the standing position or the folding position and can be rotated automatically from a neutral position to each of the above positions.