The organic-inorganic composite of the present invention includes an organic compound having a carbonyl group, an inorganic compound containing a metal component, and a silver component. The ratio of the number of metal atoms in the inorganic compound to the number of carbon atoms in the organic compound is from 0.04 to 1.60, and the ratio of the number of silver atoms in the silver component to the number of carbon atoms in the organic compound is from 0.07 to 0.55. The organic-inorganic composite may include, for example, an inorganic compound having a metal matrix structure containing a metal M and oxygen, an organic compound having a carbonyl group, and silver ions. The carbonyl group is bonded to a side chain R1 of the organic compound and has an end group R2.