All foreign visitors to the Republic of Madagascar require entry visas. Visas for less than 30 days are free but you may be asked to pay extra "fees".
A visa valid for 90 days can be obtained on arrival at Antananarivo airport for around 80 euros. Visas obtained at the airport may not be extended.
It may be easier to get a visa before arrival. Rules and fees vary between embassies.
Madagascar Consulate Visa Information