To reduce unnecessary conversion processings in order to reduce resources and shorten the response time in dynamic document conversion, and to improve the hit rate of prediction.

A document conversion apparatus (delivery server 11), which converts an electronic document into a browsable format by a terminal apparatus (client terminal 3) and delivers the converted electronic document, has a prediction conversion means (a transmission/reception unit 111; a conversion control unit 112; a document conversion unit 113; a document data storing unit 114; a conversion prediction unit 115) which analyzes a browsing trend form a browsing document in parallel with control for outputing a starting page of the browsing document requested by the terminal apparatus to predict a page, having a high possibility of subsequent browsing, and converts the predicted page into a browsable format.