PURPOSE: To enable an anchor to bite stably, deeply, and reliably during anchoring, by a method wherein ridge lines of two flukes are respectively bent inwardly to form a recess, the cross section is formed in a rhomb, and a stabilizer has a concave surface extending downward toward the outside from the lower parts on both sides of the fluke.

CONSTITUTION: Two flukes 1 and 1' at a head part A are constituted such that ridge lines 2 and 2' are respectively bent inwardly to form a recess, and the longitudinal cross section thereof is formed in a rhomb. Both sides of a body part (a) are protruded from the lower parts on both sides of each of the two flukes 1 and 1' toward the outside to form a stabilizer 3 with cross section which has a concave surface extending downward. This constitution enables increase in the surface areas of the flukes 1 and 1', and inward bonding of its rhombic cross section and the ridge lines 2 and 2' enables rapid and deep biting of an anchor during anchoring. Further, the stabilizer 3 can aid in increasing stability during anchoring.