A metal oxide particle material contains a metal oxide as a main component and has: a D50 of 1.0 m or more and 5.0 m or less, the D50 being obtained by measuring a laser diffraction particle size distribution; a specific surface area of 1.0 m.sup.2/g or more and 30 m.sup.2/g or less; a coarse particle content of 300 ppm or less, the coarse particle content being a content of coarse particles having a particle diameter of 5 m or more; and a hollow particle content of 4000 particles/10 mg or less, the hollow particle content being a content of hollow particles having a particle diameter of 5 m or more. When a resin material is filled with the metal oxide particle material at a solid concentration of 60% by mass, a resultant resin composition has a viscosity of 170 Pa.Math.s or less (at a shear velocity of 1 s.sup.1).