PURPOSE: To obtain the subject composition, having a low coefficient of moisture absorption excellent in solder heat resistance and capable of providing semiconductor packages remarkably improved in reliability by using a xylylene compound comprising an m-xylene compound as a raw material.

CONSTITUTION: This epoxy resin composition contains (A) an epoxy resin and (B) a phenolic resin as a curing agent in amounts so as to provide 0.5-1.5 equiv. ratio of OH groups in the component (B)/epoxy groups in the component (A). The component (B) is a phenolic resin obtained by reacting (i) a phenol compound with (ii) a xylylene compound of formula I (R1 and R2 are each H, a 1-4C alkyl or a 2-4C acyl), with the proviso that ≥10wt.% component (ii) is (iii) an m-xylylene compound of formula II. The component (A) is an epoxy resin prepared by epoxidizing the component (B). Furthermore, the component (ii) preferably comprises 10-100wt.% component (iii) and (iv) 0-90wt.% p-xylylene compound of formula III.