The present invention provides an optical information medium having a dye recording layer, an adhesive layer and a light transmission layer in this order on a groove provided on a substrate, wherein recording and reproduction are carried out by allowing a laser beam to enter an in-groove portion from the light transmission layer, wherein: D×W is 5,000 nm 2 or more wherein the depth of the groove is D (nm) and the width of the groove is W (nm), and the thickness of the dye recording layer in the in-groove portion is 0.7 D to 2.4 D (nm).