A biological tissue rootage face (30) capable of closely bonding to a biological tissue (H, S) is composed of a biocompatible material and has numerous fingertip-shaped microvilli (41). The microvilli (41) have tip diameters in the order of nanometers. An implant (1) has the biological tissue rootage face (30) on a surface (11, 24) configured to root into a biological tissue (H, S). In a method for forming the biological tissue rootage face (30), a surface of a biocompatible material is subjected to laser nonthermal processing carried out by emitting a laser beam in air, to form numerous fingertip-shaped microvilli (41). The laser beam is a laser beam of an ultrashort pulse laser.