During the probationary period, both you and your employer may terminate the contract without prior notice. The termination takes effect immediately, thus no notice period needs to be taken into account. The employer is required to give the reason for the termination of your employment contract upon your request.
Note: Your probationary period clause is null and void if this clause is not agreed upon in writing, exceeds the statutory deadlines and/or is not of equal length for both you and your employer.