A communication terminal includes: an update section that obtains software via a communication network from a predetermined provider so as to update the software; and a failure monitor section that monitors whether there is a failure to interfere with an update of the software by the update section. The communication terminal further includes an update record section that records, if there is the failure and the update becomes an incomplete update on an occasion of the update by the update section, the presence of the incomplete update; and an update prompting section that prompts, if a monitor result by the failure monitor section changes from that there is a failure to that there is no failure, performing by the update section the update whose presence is recorded by the update record section.