The BOJ was established in 1882, and like most central banks, it has several key functions, including:

1. Conducting monetary policy: The BOJ uses monetary policy tools such as adjusting interest rates and controlling the money supply to stabilize the economy and achieve its policy goals.
2. Regulating banks: The BOJ is responsible for supervising and regulating banks and other financial institutions to ensure the stability of the financial system.
3. Providing financial services: The BOJ provides financial services such as check clearing and electronic funds transfers to banks and other financial institutions.
4. Acting as a lender of last resort: The BOJ acts as a lender of last resort, providing loans to banks and other financial institutions during times of financial stress.

In recent years, the BOJ has implemented various monetary policy measures to combat deflation and stimulate economic growth, such as quantitative easing, negative interest rate policy and targeting the 10-year government bond yield. The BOJ has been widely criticized for not being able to reach its inflation target which is 2% but the bank has been able to maintain the stability of financial markets and support the economy during difficult times.