An electronic device for purifying air, comprising: a housing; a photocatalyst filter; at least one sensor disposed in the housing; a blower fan configured to introduce air into the housing; a light source configured to emit light to the photocatalyst filter; and a controller configured to control driving of the blower fan and the light source, wherein the controller is configured to perform communication and information transfer with at least one external electronic device (20, 30) including at least one other sensor (22, 32), determine a degree of contamination of air based on a difference in sensor values or a rate of change in sensor values between the at least one sensor disposed in the housing and the at least one other sensor (22, 33) of the external electronic device (20, 30), and perform an operation of recycling the photocatalyst filter based on the determined degree of contamination of air, wherein the photocatalyst filter includes: a body including an internal space through which the air passes; a plurality of photocatalytic beads provided in the internal space; characterised that the photocatalyst filter furthermore includes: an opening/closing part connected with the body and configured to open or close based on a flow of the air, and wherein a reflecting plate is formed on one surface of the opening/closing part to reflect light to increase an amount of light reaching the plurality of photocatalytic beads when the opening/closing part is closed. a housing; a photocatalyst filter; at least one sensor disposed in the housing; a blower fan configured to introduce air into the housing; a light source configured to emit light to the photocatalyst filter; and a controller configured to control driving of the blower fan and the light source, wherein the controller is configured to perform communication and information transfer with at least one external electronic device (20, 30) including at least one other sensor (22, 32), determine a degree of contamination of air based on a difference in sensor values or a rate of change in sensor values between the at least one sensor disposed in the housing and the at least one other sensor (22, 33) of the external electronic device (20, 30), and perform an operation of recycling the photocatalyst filter based on the determined degree of contamination of air, wherein the photocatalyst filter includes: a body including an internal space through which the air passes; a plurality of photocatalytic beads provided in the internal space; characterised that the photocatalyst filter furthermore includes: an opening/closing part connected with the body and configured to open or close based on a flow of the air, and wherein a reflecting plate is formed on one surface of the opening/closing part to reflect light to increase an amount of light reaching the plurality of photocatalytic beads when the opening/closing part is closed. wherein the controller is configured to perform communication and information transfer with at least one external electronic device (20, 30) including at least one other sensor (22, 32), determine a degree of contamination of air based on a difference in sensor values or a rate of change in sensor values between the at least one sensor disposed in the housing and the at least one other sensor (22, 33) of the external electronic device (20, 30), and perform an operation of recycling the photocatalyst filter based on the determined degree of contamination of air, perform communication and information transfer with at least one external electronic device (20, 30) including at least one other sensor (22, 32), determine a degree of contamination of air based on a difference in sensor values or a rate of change in sensor values between the at least one sensor disposed in the housing and the at least one other sensor (22, 33) of the external electronic device (20, 30), and perform an operation of recycling the photocatalyst filter based on the determined degree of contamination of air, wherein the photocatalyst filter includes: a body including an internal space through which the air passes; a plurality of photocatalytic beads provided in the internal space; characterised that the photocatalyst filter furthermore includes: an opening/closing part connected with the body and configured to open or close based on a flow of the air, and a body including an internal space through which the air passes; a plurality of photocatalytic beads provided in the internal space; characterised that the photocatalyst filter furthermore includes: an opening/closing part connected with the body and configured to open or close based on a flow of the air, and wherein a reflecting plate is formed on one surface of the opening/closing part to reflect light to increase an amount of light reaching the plurality of photocatalytic beads when the opening/closing part is closed.