If you set a regular sewing machine up with the right type of needle and adjust the presser foot tension, you can use it to sew leather.
How to Sew Leather on a Regular Sewing Machine
Install a Leather Sewing Needle
This will be a medium to large gauge needle with a fairly large eye to acccomodate the heavy thread needed, and it will have a sharp point to pierce the leather hide without tearing larger holes.
Put Leather Sewing Thread on the Machine
Set the Presser Foot Tension
The key is to remember that presser foot tension needs to be the opposite of your fabric. Heavy fabric, such as leather or denim, means light presser foot tension, while light fabric means you need heavy presser foot tension.
I won't try to tell you how to set this tension - only because each sewing machine is different - but the adjustment is typically made directly above the presser foot on top of the sewing machine's body - so check your manual, and if you can't find the info, ask and I'll see if I have or can find the details for your specific machine for you..