As a tenant, you are entitled to the peaceful use and quiet enjoyment of the property you are renting. This means that unless your lease says otherwise or there is a serious emergency, your landlord should not come onto the property without your permission.
The landlord, as owner, is entitled to have keys to your apartment. However, this does not mean that the landlord can enter at any time. The lease may have a term allowing for entry into the apartment by the owner to make repairs, perform inspections, or show the property to buyers or prospective tenants.
Generally, if repairs are needed, the landlord should give you at least 24 hours’ notice. If you want to be home at that time, you may need to rearrange your schedule. If you don’t care if you are home or not, you can give the landlord permission to enter.
In an emergency, such as burst water pipes or smoke detectors activated, your landlord has the right to enter to deal with the situation. The landlord should inform you by calling, texting or leaving a note. If you have reason to believe someone was in your apartment, contact the landlord and discuss the situation right away