An information storage medium according to the present invention has n information storage layers (where n is an integer and n≧3), on which data can be written with a laser beam and which are stacked one upon the other. Each of the n storage layers has a test write zone for determining the recording power of the laser beam. When those n layers are counted from the one that is located most distant from the surface of the medium on which the laser beam is incident, there is a bigger radial location difference between the outer peripheral end of the inner one of the test write zones of ith and (i+1)th information storage layers (where i is an integer that satisfies 2≦i≦n−1) and the inner peripheral end of the other outer test write zone than between the outer peripheral end of the inner one of the test write zones of jth and (j+1)th information storage layers (where j is an integer that satisfies 1≦j≦i−1) and the inner peripheral end of the other outer test write zone.