An apparatus is equipped with a storage device including an error correction circuit. The apparatus performs a test of the storage device according to a predetermined testing procedure, and records a time-point at which error correction of the storage device has been performed by the error correction circuit during performance of the test. The apparatus determines, with predetermined accuracy, a first position within the storage device on which the error correction has been performed, based on a test speed at which the test is performed, a time-period from the time-point to current time, and a second position within the storage device on which the test is being performed at the current time. Then, the apparatus performs the test predetermined times on a range included in the storage device and including the first position, according to a testing procedure that has been used at the time-point.