A drill in which no positional shift on a drilled hole and no irregularities on an internal wall are formed. In this apparatus, the module at the final stage is supplied with some of permeated water obtained from at least one module preceding the module at the final-stage, and a rest of the permeated water is discharged from or recovered in the apparatus along with permeated water obtained from the final-stage module. The layer has bearer manager, configuration manager, log, callback handler, blacklist and whitelist manager, billing and error functions.