Filipinos are not required to apply for a visa when entering Costa Rica. Upon entry to the country, you must have a valid passport good for another six months, and a return ticket from Costa Rica as well. You will also be required to present sufficient funds for your stay for 30 days at the maximum. Should you wish to extend your stay in the country, you may arrange that with the Department of Immigration upon arrival in the country. You will be fined for overstaying, or even deported from the country.
Yellow fever vaccination may also be a requirement especially if you just traveled, or may be traveling to, South American countries or sub-Saharan Africa.
For up-to-date information on visa requirements, it is best to consult with:
The Embassy of Costa Rica in Manila
Smith Bell Building
2294 Pasong Tamo Extension
1231 Makati City
Telephone: (632) 818-6740 / (632) 816-7851