Abstract: The object of the present disclosure is to obtain a filler particle having stable insulation property, and a resin composition, grease and a coating composition comprising the same, respectively. Filler particles comprising a composite zinc oxide expressed by the following chemical formula (1): ZnxMyO??(1) in the formula, M is Mg, Co, Li, K, Na or Cu, and x+ny/2=1 when the valence of M is n.