An anticorrosive agent including: a high-consistency material having a lubricant base oil and an amide compound, a composition of a phosphorus compound comprising one or more compounds represented by the general formulae (1) and (2) and a metal, and at least one kind of resin selected from a rosin-based resin, a terpene resin, a terpene phenol resin, a phenol resin, a coumarone-indene resin, and a petroleum resin, wherein a mass ratio of the high-consistency material and the composition is within a range of 50:50 to 98:2, and a content of resin is 2 to 20 parts by mass with respect to 100 parts by mass of the total of the high-consistency material and the composition.