An anticancer agent having a novel chemical structure and high anticanceractivity is provided. A phosphine transition metal complex of general formula(1) andan anticancer agent containing the complex are disclosed.(see formula 1)R1 and R2, which may be the same or different, each represent a group having 1to 10 carbon atoms selected from a straight-chain or branched alkyl group, acycloalkylgroup, a substituted cycloalkyl group, an adamantyl group, a phenyl group, andasubstituted phenyl group R3 and R4, which may be the same or different, eachrepresenta hydrogen atom, a straight-chain alkyl group having 1 to 6 carbon atoms orbranchedalkyl group having 1 to 6 carbon atoms or R3 and R4 are taken together toform asaturated or unsaturated ring which may have a substituted group M representsatransition metal atom selected from the group consisting of gold, copper, andsilver andX- represents an anion.
