A content processing device calculates a content topicality degree representing a degree of topicality of a content which serves as a topic between sharing users, based on subject information relating to a subjects in the content, sharing user information and social information; extracts a sharing user who does not appear in the subject of the content as an unappearing sharing user; calculates a content appropriateness degree representing a degree of appropriateness of the content to be shared between the sharing users in such a manner that the value for the content appropriateness degree decreases, as the degree of intimacy between the extracted unappearing sharing user and the subject increases; calculates a content evaluation value based on the content topicality degree and the content appropriateness degree; determines a priority based on the calculated content evaluation value; and controls output of the content according to the determined priority.