A storage system includes: a data storing means configured to store storage target data and also store address data so as to be tree-structured, the address data being based on a content and storing position of data to be referred to, and the address data referring to the storage target data or other address data; an operation log generating means configured to generate an operation log that represents a content of an operation of storing the storage target data into the data storing means and a content of an operation of storing the tree-structured address data referring to the storage target data into the data storing means; and a file system committing means configured to store the storage target data and the tree-structured address data into the data storing means based on the operation log.