Thank you for your question. Landlords are normally obliged to give you "reasonable notice" before entering the property - your lease may specify 24 hours prior notice and 24 hours prior notice is the norm.
Your lease may also specify that such notice must be "in writing". The only time a Landlord may enter without notice is in the event of an emergency; otherwise the Landlord is in breach of your covenant for quiet enjoyment. Indeed, there are circumstances where it could be considered to be harassment.
I would suggest that you check the wording of your lease for any notice requirement, and then hold him to the terms. If you find that he ignores this request you can consider taking legal action.
(Also, none of the above shall be construed as legal advice, nor does it create an attorney/client relationship. For more detailed information, feel free to contact me for a consult. Thanks!)
Mr. Bonnici is right. The only thing I have to add is, if your landlord is entering your residence for the purpose of influencing you to vacate the dwelling you could sue him in small claims court and be awarded $2000 for each violation as permitted under CA Civil Code S 1940.2(b).
-Michael R. Juarez Law Office of Juarez and Schaeffer PO Box 16216 San Diego, CA 92105 (619) 804-4327 www.jslaw.org Mike@jslaw.org This posting is provided for “information purposes” only and should not be relied upon as "legal advice." Nothing transmitted from this posting constitutes the establishment of an attorney-client relationship. Applicability of the legal principles discussed here may differ substantially in individual situations or in different jurisdictions.
Your landlord's conduct is serious. As a tenant, you have the right of "possession," meaning that you can exclude the whole world including the landlord. The only rights the landlord has are receiving your rent and getting the premises back at the end of the lease term.
Entering your house--and it is your house--without your permission is criminal trespass. You can call the police now, or you can tell your landlord that if he ever does that again you will call the police. You also have cause to terminate the lease and move out, regardless of your lease term or any lack of notice.