Yes.
The employer may include a confidentiality/discretion clause in the employment contract and thus impose upon the employee, both during the employment relationship and after it is brought to an end, an obligation of confidentiality/discretion.
Under any such clause, the employee undertakes not to disclose to third parties confidential information obtained by him regarding the activities and business relations, and in particular business secrets and manufacturing secrets, of his employer.
It should be noted however that such a clause is valid only if it is drawn up in a circumscribed and precise manner. The clause must not be a simple stylistic, vague and imprecise clause which, for example, might prohibit any indiscretion of any kind whatsoever, in which case it would not be valid.
Also, a clause of that kind is not to be confused with business secrecy, which applies by operation of law to employees working in certain professions, regardless of any clause included in their employment contract.