A wearable module is a device capable of performing short-range communication with a mobile device. A functional section executes a function which can be locked and unlocked. A list retaining section retains a password for permitting locking/unlocking of the function for each mobile device. A short-range wireless communication section receives a request for locking or unlocking a function including a password from the mobile device. A lock control section controls the function to be locked or unlocked on the basis of the password included in the request and a password retained in association with the mobile device of a request source of the request by the list retaining section.