Disclosed herein is a thermoformable film or sheet superior in gas barrier properties, mechanical properties, and appearance, a thermoformed container produced therefrom, and a resin composition suitable therefor. A thermoformable multilayer film with a total thickness of 50-300 µm, comprising a layer of a resin composition with a thickness of 3-50 µm, said resin composition comprising 60-99 wt% of ethylene-vinyl alcohol copolymer and 40-1 wt% of ethylene-(meth)acrylic acid copolymer, said ethylene-(meth)acrylic acid copolymer being dispersed in the form of particles in the matrix of said ethylene-vinyl alcohol copolymer, wherein said ethylene-vinyl alcohol copolymer having an ethylene content of 20-60 mol% and a degree of hydrolysis of not less than than 90%, and said ethylene-(meth)acrylic acid copolymer containing 1-30 wt% of (meth)acrylic acid. The EVOH may be a mixture of more than one kind of EVOH differing in ethylene content. The resin composition may contain each component dispersed in a specific manner.