To obtain a resin composition which excels in transparency, heat sealability, gas barrier properties, recycling properties, and mold processing properties.

The resin composition comprises (A) 0.1-20 pts.wt. thermoplastic polymer having a functional group (f), (B) 1-70 pts.wt. crystalline resin containing a polymer chain having a component which reacts with the functional group (f) at the terminal, and (C) 10-98.9 pts.wt. olefin based resin, and the component (C) is a continuous phase; the enthalpy (ΔHc1) of crystallization of the crystalline resin component of the component (B) having a crystallization initiation temperature of >150°C and the enthalpy (ΔHm1) of fusion of the crystalline resin component of the component (B) meet the formulae: X=ΔHc1/ΔHm1 and 0≤X≤0.7; and the melting point of the crystalline resin component of the component (B) is >150°C.