A magnetic head comprises a slider which holds recording/writing elements at its medium opposing surface constituting a lifting force generating part and the surface area of the medium opposing surface is at most 2 mm.sup.2.A magnetic recording and reproducing apparatus has such magnetic head which is disposed on a magnetic disk having a magnetic recording layer formed on a rigid substrate while the disk is rotated at a high speed so that magnetic recording and reproducing are conducted between the magnetic head and the magnetic disk, wherein the surface roughness R.sub.max of the magnetic disk is at most 100 .ANG..