XML::Twig is nice too:

use strict;
use warnings;
use XML::Twig;

my $xfile = <<EOF;
<SUB CLASSNAME="SUB1">
   <INNERSUB CLASSNAME="INNERSUB1">
        <Element1 Type="Type1">Content</Element1>
        <Element2 Type="Type2">Content</Element2>
   </INNERSUB>
</SUB>
EOF

my $t= new XML::Twig();
$t->parse($xfile);
my $sub = $t->root();

for my $elm ($sub->first_child('INNERSUB')->children()) {
    print $elm->name(),         "\n";
    print $elm->att('Type'),    "\n";
    print $elm->text(),         "\n\n";
}

__END__

Element1
Type1
Content

Element2
Type2
Content
[download]

Note: I had to modify your "element" end tags to be "Element", for legal XML.