To provide a document managing device executing the processing of high processing cost when the working rate of a processor is low, reducing storage cost and realizing document registration/retrieval with low total cost.

In the document managing device, the generation processing of a character index is executed in the case of a document registration event, the pointer of a document in the middle of processing is inserted into a word index non-processing queue and a document storage processing is executed on a secondary storage device 6. When a document retrieval event exists, retrieval is executed from the character index and retrieval is executed from the word index. The sum set of the retrieval results is obtained and the retrieval result is outputted to a display 2. When the event does not exist, the input of an operator does not exist and the device is not operated. When the word index generation non-processing queue exists at that time, the word index generation processing is executed. The character index of the document whose processing is terminated is deleted.