Can I terminate the lease as as result of the landlord entering my rented apartment without notice or my consent.

Chances are that your lease allows the landlord and the landlord's agents access to your apartment.  You will need to pull it out and read it to be sure, but that is a customary provision to have in a residential lease. It would be very uncommon for the landlord to have to give you notice or otherwise obtain your consent in order for a maintenance crew to enter, but if it isn't in your lease, then you could write to them and seek to terminate for breach of your quiet enjoyment of the lease premises.  Regardless of what the lease says, it certainly would have been courteous for them to advise you that they'd be performing maintenance on your apartment. Plus, it's in their best interest to keep you happy and from looking for another place to live when your lease is up.  I suggest that regardless of what your lease says, you write a letter of complaint to your landlord as it is imperative that you feel safe in your home.    This should ensure that you receive notice next time or that they don't enter without your permission at the time.