Provided is a thermoformed container having a superior appearance as a result of inhibition of coloring and generation of defects during the melt molding, having sufficient strength, and further having a self-purge feature in a production process. The thermoformed container includes an EVOH layer (A) containing an ethylene-vinyl alcohol copolymer (I) as a principal component, wherein the EVOH layer (A) contains a carbonyl compound (II), the carbonyl compound (II) is an unsaturated aldehyde (II-1), a saturated aldehyde (II-2), a saturated ketone (II-3) or a combination thereof, and the content of the carbonyl compound (II) in the EVOH layer (A) is 0.01 ppm or greater and 100 ppm or less. The carbonyl compound (II) is preferably an unsaturated aldehyde (II-1), and the unsaturated aldehyde (II-1) is preferably an unsaturated aliphatic aldehyde.