The nearby radio galaxy M87 offers a unique opportunity for studying the accretion and
ejection processes near a supermassive black hole (SMBH). Following the first
successful imaging of the SMBH with the Event Horizon Telescope, significant advances
have been made for observations of this black hole in the past few years especially
thanks to high-resolution very-long-baseline-interferometry (VLBI) instruments as well
as efforts of joint multi-wavelength observations. In this talk I will overview the
recent progress of various high-resolution studies on the M87 SMBH, jet and accretion
flows.