A Vanin-1 inhibitor includes as an active ingredient a pantotheine ketone derivative represented by the following Formula (I), wherein X, Y, Y′, Z, and Z′ are independently selected from a hydrogen atom, a fluorine group, and a substituent substituted with a fluorine group, and at least one of X, Y, Y′, Z, or Z′ is a fluorine group or a substituent substituted with a fluorine group.