A dialog device for executing a conversation with a user using a conversational sentence generated from content information is provided. The dialog device includes an information acquisition unit that acquires the content information from an information source, and changes the content information used in generation of the conversational sentence, and continues the conversation with the user. The dialog device sets multiple attribute information pieces with respect to specific content information used in generation of the conversational sentence. The dialog device controls the information acquisition unit to acquire other content information, having at least a part of attribute information pieces equal to the specific content information, as a candidate used in generation of the conversational sentence next to the specific content information.