The main purpose of a microfinance bank is to provide financial services, such as loans, savings accounts, and insurance, to individuals and small businesses who typically lack access to traditional banking services. Microfinance banks aim to promote financial inclusion, alleviate poverty, and support economic development by offering these services to people in underserved or low-income communities. They often specialize in providing small, affordable loans to help individuals start or expand small businesses and improve their livelihoods.