In a storage controlling apparatus controlling an access from a host to a disk apparatus, for example, when a data transfer confirmation flag set in a data transfer descriptor is "ON", a data transfer confirmation descriptor is automatically generated on the basis of transfer information in the data transfer descriptor, data is transferred to a management module according to the data transfer descriptor, and a confirmation code is read out from a bridge module according to the data transfer confirmation descriptor after data transfer to the management module is completed. Whereby, the load on the CPU and the number of PCI accesses are decreased so that the input/output performance is improved.