Zinc pyrithione and copper pyrithione are highly evaluated in the market as an antidandruff agent for shampoo, or an antifouling agent for ship bottom paint and fish-farming net, or an antibacterial/antifungal agent or preservative/mildewcide for industrial products and household articles. For enhancing the market value thereof, there has been a demand for a product that not only attains an increase in conventional antibacterial/antifungal effects but also exhibits novel bioactive effects and that achieves improvement with respect to problems and drawbacks relating to properties, such as solubility in seawater, and stability, such as thermal stability and weather resistance, of polymer materials. There is provided a novel pyrithione complex compound obtained by converting the conventional pyrithione metal salt to a complex compound with an oxide or hydroxide of metal such as zinc, copper or aluminum. As compared with the conventional pyrithione metal salt, this complex compound exhibits superior antibacterial/antifungal effects, newly realizes a hair-regrowing effect and successfully attains improvement with respect to the solubility in seawater and thermal stability/weather resistance of polymer materials.