A control apparatus which is used to control an Internet of things apparatus, comprising: communication circuitry; a sensor; and a processor configured to: control the communication circuitry to transmit a request for establishing a connection, to the Internet of things apparatus, control the sensor to sense a physical signal which is output from the Internet of things apparatus in response to the request for establishing the connection, recognize the physical signal as a response signal output from the Internet of things apparatus, the response signal being a signal whose transmission distance is limited within a radius, control completion of establishment of the connection to the Internet of things apparatus, based on recognizing the response signal, in response to recognizing the response signal whose transmission distance is limited within the predetermined radius, determine that a user of the control apparatus is an authorized user of the Internet of things apparatus, and based on the determination, register, in a server, connection information indicating an established relationship between the user of the control apparatus and the Internet of things apparatus; wherein once the connection information has been registered in the server, the control apparatus is arranged to access and control the Internet of things apparatus through the server. communication circuitry; a sensor; and a processor configured to: control the communication circuitry to transmit a request for establishing a connection, to the Internet of things apparatus, control the sensor to sense a physical signal which is output from the Internet of things apparatus in response to the request for establishing the connection, recognize the physical signal as a response signal output from the Internet of things apparatus, the response signal being a signal whose transmission distance is limited within a radius, control completion of establishment of the connection to the Internet of things apparatus, based on recognizing the response signal, in response to recognizing the response signal whose transmission distance is limited within the predetermined radius, determine that a user of the control apparatus is an authorized user of the Internet of things apparatus, and based on the determination, register, in a server, connection information indicating an established relationship between the user of the control apparatus and the Internet of things apparatus; wherein once the connection information has been registered in the server, the control apparatus is arranged to access and control the Internet of things apparatus through the server. control the communication circuitry to transmit a request for establishing a connection, to the Internet of things apparatus, control the sensor to sense a physical signal which is output from the Internet of things apparatus in response to the request for establishing the connection, recognize the physical signal as a response signal output from the Internet of things apparatus, the response signal being a signal whose transmission distance is limited within a radius, control completion of establishment of the connection to the Internet of things apparatus, based on recognizing the response signal, in response to recognizing the response signal whose transmission distance is limited within the predetermined radius, determine that a user of the control apparatus is an authorized user of the Internet of things apparatus, and based on the determination, register, in a server, connection information indicating an established relationship between the user of the control apparatus and the Internet of things apparatus; wherein once the connection information has been registered in the server, the control apparatus is arranged to access and control the Internet of things apparatus through the server.