Not unless it is IPX rated.
Under the Electrical Safety Standards only electrical products that are IPX rated can be used in a bathroom. As generally our dehumidifiers are not IPX rated, you must not use it in a bathroom.
What you can do is place it outside the bathroom (where you are certain that there will be no water splashing onto the dehumidifier) with the door opened if you need to remove condensation from the bathroom. You must ensure that it is placed at a safe proximity from any possible water splash.