The invention relates to a treatment plate (10) for a garment treatment appliance (100) for treating garments (30), which plate has a contact surface which is provided with a sol-gel coating (20) that comprises an oxide of titanium, zirconium, hafnium, scandium, yttrium, or a mixture or combination thereof, and wherein the coating comprises a mixed oxide comprising two or more of titanium oxide, zirconium oxide and yttrium oxide. The layer preferably has a thickness of less than 1 μm. Such a layer shows excellent properties. A garment treatment appliance comprising such a treatment plate, as well as processes to produce the coating on the contact surface of the treatment plate are also disclosed.