To form a highly water-repellent surface on a foam to inhibit water from permeating into the foam and from icing on its surface in cold districts.

This foam has a water-repellent fluororesin surface which comprises an amorphous porous body having an uneven surface and formed by heaping fluororesin particles having an average particle size of 1μm or lower. The surface has a tangent value of a water-rolling angle (the smallest inclination of a surface causing water droplets to roll down there along) of 50/500 or lower and is formed by dispersing fluororesin particles in a medium comprising water, an org. solvent, or their mixture contg. 0.5wt.% or lower (based on the particles) surfactant, applying the resultant dispersion to the surface of a foam, and drying the foam at a temp. lower than the fusion-starting temp. of the particles in such a state that the particles can be in contact with each other, thus fixing the particles to the surface.