Start at the school, not at the state
A school record travels only as a signed sheet the state can check. Begin at the school or faculty that issued it and ask for a sealed copy, or the substitute certificate they write when the parchment must stay with you. The state desk will not touch a home photocopy, and it will not touch the parchment itself when the signature on it cannot be traced.
An apostille is one extra certificate laid over that seal. It tells a reader abroad that the seal and the signature are genuine, so no embassy step follows for countries inside the Hague circle. To apostille a diploma in Italy you carry the sealed copy to the state desk, pay the stamp and wait. Italy joined that circle in 1978, so the work is routine.
Which desk signs a Catania school paper
A school record counts as an administrative paper, so it belongs to the Prefettura, the arm of the state in each province. Judicial and notarial acts take another road, and are signed by the Procura della Repubblica at the court instead. Your diploma is not a court paper, so the provincial queue is yours. Choosing the wrong building is the commonest wasted morning in the whole errand.
If you are working out how you apostille a diploma that belongs to someone else, bring written power from them. The desk reads who is standing in front of it as well as what is on the sheet. A parent of an adult child has no automatic standing, and a photographed mandate is often turned away. Get the mandate signed on paper before you queue.
Why the signature must already be on file
The stamp vouches for a signature, so that signature has to be known to the state already. Ask your school or faculty which office holds the specimen of whoever signed your copy, and whether it has been sent on. When a head of school is new, or the specimen is missing, the desk has nothing to match and will refuse. Sorting that out is the school's job, not yours.
What the stamp costs
The apostille cost for a diploma in Catania is a €16 tax stamp on each sheet, and the law exempts some papers. Buy the stamp at a tobacconist before you queue, because the desk takes no cards. If you hold several years of results as separate sheets, each one carries its own stamp, so count them at home. No fixed waiting time is published, so treat a same-day stamp as luck.
Course places and employers overseas
A place on a course is the usual reason to apostille a diploma in Catania. An admissions office abroad wants proof that the school exists and that your marks are real. Employers ask for the same sheet when a licence or a public post is at stake. Some want the results transcript beside the diploma, so read the list they sent you line by line.
Legalisation of a diploma in Catania is the older route, kept for countries that stay outside the Hague circle. It adds a consular signature after the state stamp, and each consulate sets its own extras. Whether your destination takes the apostille or wants that longer chain is for the receiving authority to say, so ask them before you start.
What the stamp does not do
A stamp is not recognition. It says the paper is genuine; it says nothing about whether a foreign body will treat your studies as equal to its own. That second question belongs to the ministry or the school in the receiving country, and usually needs its own file. Ask them early, because such a ruling takes far longer than any stamp.
Language is the other loose end. The stamp moves no words across, so a reader who cannot follow your record will want a sworn version. Ask the receiving office in writing which language they need, then order only that. Guessing here is how people end up paying twice for one sheet.