I am quite acquainted with the problems which arise from the regulations of the Spanish tenancy laws. You do have a problem if the tenant decides to stick to the law. These provisions stipulate that a tenant will be entitled to renew the agreement per years up to a maximum of 5 (these provisions are mandatory), unless there is an express condition in the contract stating that the landlord will need the property for himself and he does effectively take possession of the property within three months of the termination of the contract period.
The abscence of this clause gives more protection to the tenant and vacating him may be a difficult task. Since I do not know the terms of your contract, I can't help you much more.
However, you should be prepared if so to go through a Court procedure to obtain an eviction order. Don't forget that letting is a business itself, and as any other, is not risk free. Again, every case is different and a more careful look into the specific situation you are in now is of the essence in order to proceed further.
