PURPOSE: To provide a surface grinding machine to carry out R curved surface forming machine work highly accurately on a medium sliding surface of a magnetic head.

CONSTITUTION: A surface grinding machine has an R curved surface forming means of a medium sliding surface of a magnetic head 15, a measuring means to measure dispersion of gap depths for respective tracks in the magnetic head 15 at R curved surface grinding time, that is, a difference in both gap depths in both end tracks and an angle correcting table 10 to carry out angle correction on an inclined angle corresponding to a difference in the gap depths in R grinding work according to a value measured by the measuring means. The R curved surface forming means uses a grinding wheel 8 where a surface coming into contact with the magnetic head 15 being a grinding object is formed in an R curved surface shape, and a preset position of the R shape grinding wheel 8 is situated in the vertical direction to the medium sliding direction of the magnetic head 15. With constitution in this way, a grinding process can be easily automated.