The deforming of thin metal films on PET substrates is studied. Though only polymer substrates are deformed in conventional nanoimprint lithography studies, we pressed metal-polymer composite specimens which may be applied to micro electromagnetic or optical devices. 100 nm Al thin films were deposited on 50 μm PET substrates for specimens. The thin metal films on PET are pressed for loading time t=300, 900, 1800 s with a mold patterned lines. As a result, thin metal films are strained 1.7 % at most.