The resin composition contains (A) a resin and (B) an inorganic filler. The component (B) contains (b1) anhydrous magnesium carbonate and (b2) aluminum oxide. The content of the component (b1) is in the range of 35% by volume or more and 65% by volume or less with respect to the total 100% by volume of the component (b1) and the component (b2). The content of the component (B) is in the range of 60% by volume or more and 75% by volume or less with respect to 100% by volume of the resin composition.