Abstract: Provided is an IoT data collection system 100 including an agent device 10 configured to acquire IoT data, a management device 20 configured to manage the agent device 10, and a server device 30 configured to receive the IoT data from the agent device 10. The agent device 10 includes a first transmission unit configured to transmit an authentication activation key to the management device 20 at startup. The management device 20 includes a collation unit configured to collate a registered activation key and the authentication activation key, and a transmission unit configured to transmit an authentication agent ID to the agent device 10 when the collation result is matched. The agent device 10 further includes a second transmission unit configured to transmit the IoT data and the authentication agent ID to the server device 30.