To provide an epoxy resin composition which can carry out the electrodeposition coating on the surface after the curing, is excellent in the physical properties as an adhesive, and has a low viscosity and a low specific gravity.

The epoxy resin composition includes as principal components an epoxy resin (A), an ammonium chloride salt compound (B) expressed by RaN+HbCl- (R is an organic group; a is 1, 2, or 3; b is 1, 2, or 3; and a+b is 4), and a latent catalyst (C), wherein this epoxy resin composition of a heat hardening-type contains 3-30 pts.mass of the ammonium chloride salt compound (B) relative to 100 pts.mass of the epoxy resin (A).