An object of the present invention is to provide a composite oxide particle material formed of zinc molybdate having a high purity and a high circularity. The composite oxide particle material is formed of a composite oxide, of molybdenum and zinc, having an average particle diameter of 0.1 μm or more and 5.0 μm or less, a BET specific surface area of 1 m2/g or more and 20 m2/g or less, (peak intensity at 26.6° according to XRD)/(peak intensity at 24.2°) of 1.20 or more, an impurity concentration of 1 mass % or less, and a circularity of 0.90 or more. XRD is measured with CuKα radiation.