There are three ways to apply for a Tourist or Business Visa for Panama :-

(A) If the applicant is holding a valid and at least once travelled multiple entries visa for the following countries USA, UK CANADA, AUSTRALIA, EUROPEAN OR SCHENGEN STATES. The applicant is entitled to take an on arrival visa at the Panama Airport for USD 35. Please note the visa should not be a transit visa. Following documents are required:-

Two visa application forms duly filled in original and completed in block letters without any scratches/ white liquid etc.
Applicant should have a passport valid for at least 6 months at the time of arrival. The passport should have minimum two adjacent blank pages for visa stamp.
3 passport size photographs in a clear white background.
Photocopy of the passport along with visas obtained, e.g. USA UK etc. Two sets required.
A letter from the company stating that the Applicant is representing the company to go to Panama.
A Covering letter from the applicant stating the purpose and duration of stay, along with his/her personal and passport details.
Itinerary showing entry and exit from Panama.
Hotel Confirmation (wherever applicable).
Proof of sufficient fund for the entire duration of stay in Panama.
(B) If the applicant is not holding any visas as per the 1st point mentioned above, the applicant can apply for his visa through a lawyer in Panama.
(C) If the Applicant is not holding any valid visa, then following documents are the requirements:-

Two visa application forms duly filled in original and completed in block letters without any scratches/ white liquid etc.
Applicant should have a passport valid for at least 6 months at the time of applying. The passport should have minimum two adjacent blank pages for visa stamp.
3 passport size photographs in a clear white background.
Photocopy of the passport of all the pages along with visas obtained, e.g. USA UK etc. Two sets required.
A letter from the company stating that the Applicant is representing the company to go to Panama.
Invitation Letter from the company in Panama along with a copy of public registry / incorporation, copy of key operations, in case of Free Zone, a copy of their key operations, copy of the receipt which would show the company address.
Photo ID copy of the sponsor.
A scan copy of the Bank Solvency letter of the Sponsor.
Bank Solvency letter of the Applicant with the name of the Manager and the seal of the Bank. The solvency should be shown through the following documents/any one:
Through travelers cheques.
Bank Certificate with the last three months balance.
Income Tax Declaration-of the last one year.
Salary Slips for last three months.
A copy of the Applicant's Pan Card, Voter ID card and Driving License.
ID card copy of the Applicant.