PURPOSE: To obtain an epoxy resin composition having excellent handleability and workability owing to long pot-life and having physical properties necessary for a resin material for electronic part such as high mechanical strength and low hygroscopicity.

CONSTITUTION: The epoxy resin composition is produced by compounding (A) an epoxy compound having ≥2 epoxy groups (e.g. bisphenol A epoxy resin) with (B) a modified aliphatic polyamine compound of formula (x, y, z and N=x+y+z are integers of ≥0; R1 and R2 are H, alkyl, hydroxyl or phenyl) as an amine-based hardener. The equivalent ratio of the component B is generally 50-150% based on the epoxy equivalent of the component A. The component A preferably has a chloride ion content of ≤10ppm in order to use the composition in electronic parts.