Here is the answer from the manufacturer:
"We advise you to hand wash your knife and flatware under gently running hot water and to wipe it immediately after. However, most knives and flatware, but not those with natural wood handles and in real horn, are dish-washer safe.
It is essential to comply with the following recommendations:
Place knives in a different compartment from other flatware
Avoid long washing cycles, do not use temperature over 122°F
Open the dish-washer as soon as the cycle is finished
Do not leave knives and flatware in the dish-washer for several hours after a washing cycle is finished
When you take them out of the dish-washer and before putting them away, dry with a soft cloth
The cutler’s trick +: do not put ordinary steel articles in your dishwasher (jam’s jars lids …) the corrosion of these during the washing cycle would lead deposits of rust on your flatware!"