Hard and brittle materials such as ceramics and glass are not only difficult-to-machine but also occur easily cracks at the exit surface in through-hole drilling. This paper deals with through-hole drilling of glass plate for plasma display panel using an electroplated abrasive grain tool in order to find out drilling conditions for smaller cracks, higher drilling efficiency and longer tool life. In particular, the influence of the crack in two kinds of abrasive grain is examined. The main conclusions obtained in this study are as follows. The crack in diamond grain tool is smaller than that in CBN grain tool. Moreover, the tool life of diamond grain tool is longer than that of CBN grain tool. Adhered volume of chip increases with drilling numbers, so the crack size and the thrust force increases. The washing of tool is required in order to restrain crack and force.