The invention comprises a unit and system for remote monitoring and controlling of various conditions in a container during cargo. The system includes a local wireless or cable (wired) network with a local station and access points positioned in the vicinity of location of containers, a remote central station connected with the Internet and a container-mounted means for monitoring and control of reefer equipment, each of which includes a processor (CPU) and a transceiver of wireless local communication, a GPS-receiver and a transceiver of cellular communication (with all of them being connected to the said processor). In addition the processor (CPU) of the device is connected to the controller of reefer equipment, while the transceiver of wireless local communication is made so that the creation of Personal Area Network (PAN) with mobile electronic devices (e.g., Notebook, Pocket PC, PDA) is possible, and establishment of wireless communication with a communication gateway of the said local network is also possible.