Abstract: PURPOSE: To provide a resin composition excellent in pattern-embedding property, adhesion, heat resistance, flexibility and printability, and a semiconductor device using the same. SOLUTION: The present invention relates to a resin composition comprising (A) an aromatic thermoplastic resin soluble in a polar solvent at room temperature, (B) an aromatic thermoplastic resin not soluble in the polar solvent at room temperature but soluble by heating, (C) a filler having rubber elasticity of which an average particle diameter is 0.1 to 6 ?m and a particle diameter distribution is 0.01 to 15 ?m and (D) the polar solvent, wherein viscosities of the resin composition measured at frequencies of 5 Hz and 50 Hz under a shear stress of 13 Pa by using a rheometer are less than 400 Pa·s and not less than 3 Pa·s, respectively, and a ratio of those viscosities (viscosity at 5 Hz (Pa·s)/viscosity at 50 Hz (Pa·s)) is not less than 2.