Silica particulate filled epoxide resins are used as encapsulant materials in semiconductor packaging. In the present paper, fracture behavior of the epoxide resin, containing 70 wt% silica particles, have been studied at room temperature and high temperature, that is, 250°C. The three-point and four-point bending tests were performed to obtain Mode I and mixed-mode fracture toughness, respectively. The specimen fractured in a brittle manner under room temperature conditions, and the results obeyed the maximum hoop stress criterion. On the other hand, the results at high temperature showed a relatively low dependency on Mode II stress intensity factors. Fracture surface were observed in a scanning laser microscope. Finite element analysis, taking into account the microstructure of the material, have been conducted in order to investigate the influence of temperature on mixed-mode fracture behavior. Local fracture criteria were considered for the silica particles and the epoxide resin. The material constants in criteria were estimated from the bending strength and the Mode I fracture toughness of the material. Good agreement between experimental and numerical results was obtained for the fracture boundary curves on the Mode I and Mode II stress intensity diagram.