A maintenance support system that supports maintenance of an air conditioner system including a plurality of air conditioners (250, 251, 252) disposed in one room and connected to a communication line, the maintenance support system comprising: a server connected to the air conditioner system via the communication line, the server storing at least one of position information, individual identification information, operation information and abnormality history of each of the air conditioners; and a portable terminal connected to the server via the communication line, the portable terminal receiving at least one of the individual identification information, the operation information and the abnormality history of each of the air conditioners from the server, characterized in that the portable terminal includes: an image pickup unit that acquires a picked-up image; a positioning unit that detects information concerning a present position of the portable terminal; and a posture detecting unit that acquires information concerning a posture of the portable terminal; a control unit that specifies, on the basis of the position information, the air conditioner included in the picked-up image, calculates relative positions of the air conditioners with respect to the portable terminal on the basis of the information concerning the present position of the portable terminal and the position information of the air conditioner, specifies a position of the air conditioner included in the picked-up image on the basis of an angle of view of the picked-up image, the information concerning the posture of the portable terminal and the relative positions, and creates an image obtained by superimposing, on the air conditioner included in the picked-up image, at least one of the individual identification information, the operation information and the abnormality history of the air conditioner; and a display unit that displays the image created by the control unit. a server connected to the air conditioner system via the communication line, the server storing at least one of position information, individual identification information, operation information and abnormality history of each of the air conditioners; and a portable terminal connected to the server via the communication line, the portable terminal receiving at least one of the individual identification information, the operation information and the abnormality history of each of the air conditioners from the server, characterized in that the portable terminal includes: an image pickup unit that acquires a picked-up image; a positioning unit that detects information concerning a present position of the portable terminal; and a posture detecting unit that acquires information concerning a posture of the portable terminal; a control unit that specifies, on the basis of the position information, the air conditioner included in the picked-up image, calculates relative positions of the air conditioners with respect to the portable terminal on the basis of the information concerning the present position of the portable terminal and the position information of the air conditioner, specifies a position of the air conditioner included in the picked-up image on the basis of an angle of view of the picked-up image, the information concerning the posture of the portable terminal and the relative positions, and creates an image obtained by superimposing, on the air conditioner included in the picked-up image, at least one of the individual identification information, the operation information and the abnormality history of the air conditioner; and a display unit that displays the image created by the control unit.