Safety device (1) for holding and sharing among a plurality of users a key (100) provided with a remote control (102). The safety device (1) includes: an external housing (2) adapted to internally contain said key (100), configurable according to an open configuration and a closed configuration; a lock (5) that can be commanded for switching between a closed status, that prevents said external housing (2) in the closed configuration from switching into the open configuration, and an open status, that enables the external housing (2) to switch between the open and the closed configurations; means for interacting with said remote control (102) of the key (100); a transmission unit (18) configured to receive, directly or via an external server (107), command signals from an external command device (19); and a command and control unit (17).