It is preferable that this first recording/reproducing method further includes a second step, carried out after the first step, wherein, when recording or reproducing signals on a recording layer C of the second optical recording medium that is different from the recording layer B, the spherical aberration correction means is driven so as to correct {HEAD ~ spherical aberration} of {TAIL ~ that recording layer C} 
It is preferable that this first recording / reproducing method further includes a second step , carried out after the first step , wherein , when recording or reproducing signals on a recording layer C of the second optical recording medium that is different from the recording layer B , the spherical aberration correction means is driven so as to correct { HEAD ~ spherical aberration } of { TAIL ~ that recording layer C }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL