Yes, combination wall ovens are safe to use. However, certain safety precautions should be followed when using a combination wall oven as with any appliance.
For example, always make sure that the power cord is correctly plugged into a grounded outlet and never leave the oven unattended while it is in use. Additionally, always follow the manufacturer's instructions when using the oven.
By following these safety precautions, you can help ensure that your experience with a combination wall oven is safe.