Abstract: A recessed and protruding structure for handling sand for a pet and a mat having the structure, the structure capable of removing sand or the like attached to the pet such as a dog and a cat and especially sand attached to paws of a cat by spreading apart toes without straining them during walking of the pet, is provided. A plurality of protrusions independent of each other at least at their tip end portions are provided on a base portion of the mat. A height of each independent protrusion is greater than 6 mm and smaller than 11 mm, a diameter of each independent protrusion is greater than or equal to 3 mm and smaller than 6 mm, intervals between the independent protrusions are longer than 3 mm and shorter than 9 mm, and toes of paws of the pet spread apart and the sand between the toes falls off when the pet walks on the independent protrusions.