In this sealing surface processing machine and method, provided are: a pedestal (10) which is attached to a valve main body (110); a main body (20) which is movably supported on the pedestal (10); a tool holder (60) for holding a cutting tool (T) for processing an attachment surface (114); a main shaft (40) which rotates the tool holder (60) relative to the main body (20), around an axis parallel to the movement direction of a valve element (124); a first moving part (30) which is capable of moving the tool holder (60) relative to the main body (20), along the Z-axis direction along which the valve element (124) moves; a second moving part (50) which is capable of moving the tool holder (60) relative to the main body (20), along the X-axis direction and the Y-axis direction which intersect the movement direction of the valve element (124); a first adjustment device (70) which adjusts the position of the main body (20) in the Z-axis direction relative to the pedestal (10); and a second adjustment device (80) which adjusts the position of the main body (20) in the X-axis direction and the Y-axis direction relative to the pedestal (10).