An information recording medium having at least a read only area and a
recording and reproducing area is composed of at least: a substrate; a
recording layer formed on the substrate so as to record and reproduce
information; and a light transmission layer having transparency formed on
the recording layer. The information recording medium is further
characterized in that a wobbling groove corresponding to the read only
area and another wobbling groove corresponding to the recording and
reproducing area is formed on the substrate without overlapping with each
other, the recording and light transmitting layers are continuously
adhered over at least two areas of the read only area and the recording
and reproducing area, reflectivity of the recording layer is more than
5%, and a push-pull signal output T3 reproduced from the read only area
and another push-pull signal output T4 reproduced from the recording and
reproducing area before recording satisfies relations of T3.gtoreq.0.1,
T4.gtoreq.0.1 and 1.5.gtoreq.T3/T4.gtoreq.0.5.