A service system in an IoT environment is provided. The service system includes an instance manager configured to manage generation and operation of an instance for a virtual object corresponding to an IoT device. The instance manager includes an instance pool configured to pool the instance, a message router configured to filter a data stream according to the instance and to transmit the filtered result value together with the data stream, and an instance lifecycle manager configured to reuse the instance pooled in the instance pool according to the filtered result value or to skip calling of an instance according to the data stream.