Antibacterial material, antibacterial material dispersion liquid, antibacterial material dispersion body, and method for producing them

A method for producing an antibacterial material, comprising:

• a first step of producing a composite tungsten oxide having a hexagonal crystal structure expressed by a general formula MxWyOz (wherein, element M include one or more elements selected from H, He, alkali metals, alkaline earth metals, rare earth elements, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, TI, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, and I, W is tungsten, O is oxygen, and 0.01≤x/y≤1.0, 2.2≤z/y≤3.0);
• and
• a second step of mechanically pulverizing the composite tungsten oxide obtained in the first step, to produce composite tungsten oxide fine particles having a lattice constant in a hexagonal crystal structure in which a-axis is 7.3850 Å or more and 7.4186 Å or less and c-axis is 7.5600 Å or more and 7.6240 Å or less, and having a particle size of 100 nm or less.