A production method for a composite material that contains a filler, a polymerizable monomer, and a polymerization initiator, said production method being characterized by comprising the mixed polymerizable monomer preparation step, the silane treatment step, the silane-treated filler storage step, and the composite material production step that are described below. The mixed polymerizable monomer preparation step is a step in which the polymerizable monomer is mixed with the polymerization initiator in order to prepare a mixed polymerizable monomer. The silane treatment step is a step in which a silane treatment liquid having mixed therein 1 to 40% of a silane coupling agent and 99 to 60% of an organic solvent and/or water is prepared, the filler is inserted into a mixing container, and an amount of the silane treatment liquid corresponding to 1 to 15% of the silane coupling agent with respect to the filler amount is dripped into the mixture at a temperature in the range of 1 to 60 °C for a mixing time of 1 minute to 24 hours in order to produce a silane-treated filler. The silane-treated filler storage step is a step in which the silane-treated filler that has been subjected to silane treatment is stored for 30 to 600 days. The composite material production step is a step in which the mixed polymerizable monomer and the silane-treated filler are mixed in order to produce the composite material.La présente invention concerne un procédé de production d'un matériau composite qui contient une charge, un monomère polymérisable et un initiateur de polymérisation, ledit procédé de production étant caractérisé en ce qu'il comprend l'étape de préparation du monomère polymérisable mélangé, l'étape de traitement au silane, l'étape de stockage de la charge traitée au silane, et l'étape de production du matériau composite. L'étape de préparation du monomère polymérisable mélangé est une étape dans laquelle le monomère polymérisable est mélangé avec l'initiateur de polymérisati
