A blow molded container including (A) a layer containing an ethylene-vinyl alcohol copolymer as a principal component, in which the layer (A) contains an unsaturated aldehyde, and the content of the unsaturated aldehyde in the layer (A) is 0.01 ppm or more and 100 ppm or less. The unsaturated aldehyde (II) is preferably an unsaturated aliphatic aldehyde. The unsaturated aldehyde (II) is preferably at least one selected from the group consisting of crotonaldehyde, 2,4-hexadienal and 2,4,6-octatrienal. The layer (A) preferably contains a conjugated polyene compound, and the content of the conjugated polyene compound in the layer (A) is preferably 0.01 ppm or more and 1,000 ppm or less.