how to keep output of apt-get in a file ?

[Khalid EZZARAOUI <ezak@cybercable.fr>]

did someone know if apt-get keep it's output somewhere, or the way to do
it ?
    because the long list of thing to do during the install ?

    I try :
        apt-get upgrade 1>&2 apt-get_output.txt
    but I don't see what is wrong.

thanks.