An information recording medium reading method is provided. The information recording medium has a user data area for recording data and at Least one spare area for recording replacements for defects of the user data area. The method includes steps of sequentially reading the user data area upon a registered defect is read. searching a corresponding replacement for the registered defect in a cache buffer; reading the corresponding replacement and neighboring replacements thereof from the spare area if the corresponding replacement is failed to be found in the searching step; storing the read replacements in the cache buffer; and repeating the above steps until a reading procedure is completed. A reading apparatus, which includes the cache buffer for storing the replacements and implements the above method, is also provided.