An arithmetic processing apparatus includes a cache memory to store data in cache lines, an error detecting unit to detect an error occurring in one of the cache lines, a way comparing unit to compare way identification information of a cache line to be accessed with error-way identification information, a word comparing unit to compare a word address of the cache line to be accessed with an error word address, a column comparing unit to compare a column address of the cache line to be accessed with an error column address, and a control unit to disable all cache lines sharing a failed word line in response to results of comparisons made by the way comparing unit, the word comparing unit, and the column comparing unit when the error detecting unit detects a second error occurring in any one of the cache lines after the occurrence of the first error.