thickness of 25 nm the reflection layer was an alcr alloy layer as of example 1 and having a thickness of 80 nm the sin layer was formed by radio frequency sputtering with a sintered si 3 n 4 target in an ar gas atmosphere the ratio of si to n in the sin is considered to be deviated from the stoichiometric ratio of 3 4 but the precise ratio could not be determined the transparency of the sin layer was excellent and the refractive index of the layer was 2 15 as a result significant deformations of reproduced signal wave shape due to peeling of the layer or formation of cracks were observed the peak shift due to a flow of the recording layer was as large as 25 u03bc sec the bit error rate was as large as 2 10 4 it was considered that provision of the thick zns layers on both sided of the recording layer caused deterioration of the repetition durability even in comparison with the sample without any adhesion promotion layer of comparative example 1 a phase change optical recording medium having the structure of a transparent substrate 1 a first transparent dielectric protecting layer 2 a recording layer 3 an adhesion promotion layer 4 a second transparent dielectric protecting layer 5 a reflection layer 6 a uv cured resin protecting layer 7 was manufactured as in example 1 except that the first and second protecting layers were of zns y 2 o 3 the adhesion promotion layer was an sio 2 layer the zns y 2 o 3 layer was formed by radio frequency sputtering a sintered zns y 2 o 3 target zns y 2 o 3 90 10 by.