In a DVD-R, lands 1 and grooves 2 are alternately formed in a spiral
configuration; the lands 1 form projecting parts, and the grooves 2 form
recessed parts 2. Recorded information is written into the grooves 2,
while land pre-pits 3 are formed in some portions of the lands 1. The
land pre-pits 3 form recessed parts, and the respective land pre-pits 3
cover the entire width of the corresponding land 1 as shown in the
figures. These land pre-pits 3 are arranged so that
a>b>0.5.times.a, where a is the maximum length of the land
pre-pits, and b is the minimum length (ordinarily, the minimum length is
the shorter of the lengths b1 and b2 of the land pre-pits in the
circumferential edge portions of the lands (i.e., the boundary portions
with the grooves)). Furthermore, the value of a is set at 0.2 .mu.m to
0.4 .mu.m.