To provide a data collecting system and device capable of easily collecting data, using a dimple constitution.

A receiving unit 1 is loaded on an automobile M, and when the automobile M comes to a communication range, a decoding key transmitted by radio from a transmitting unit 3 is received; and a storage unit 2 connected detachably to the receiving unit 1 is allowed to store the decoding key. A reproducing unit 4 acquires enciphered contents from a recording medium, and when the storage unit 2 is connected to own reproducing unit 4, acquires the decoding key stored in the storage unit 2. Then, the reproducing unit 4 decodes the enciphered contents data by using the acquired decoding key, and reproduce the contents indicated by the data acquired through decoding.