An air conditioner comprising: an indoor unit; an outdoor unit; a relay circuit including a contact and a relay coil; a control unit to cause a first voltage equal to or higher than an operating voltage for turning ON the contact or a second voltage lower than the operating voltage and equal to or higher than a retention voltage for retaining a state in which the contact is ON to be applied to the relay coil; and one end portion of two end portions (4p, 4q) of the contact is connected to an alternating-current power supply and another end portion of the two end portions (4p, 4q) of the contact is connected to the outdoor unit, one end portion of two end portions (4x, 4y) of the relay coil is connected to a power supply for driving the relay circuit, and the control unit is configured to cause the first voltage to be applied to the relay coil at a start of an ON state of the contact, cause the second voltage to be applied to the relay coil after the contact is turned ON, characterized by further comprising an abnormality detection unit configured to, when an abnormality occurs in the outdoor unit, detect occurrence of the abnormality in the outdoor unit, and the indoor unit including a notification unit configured to, when the abnormality detection unit detects that an abnormality has occurred in the outdoor unit, notify that the abnormality has occurred in the outdoor unit after confirming that the abnormality occurring in the outdoor unit has continued for a predetermined period, the control unit being configured to cause the first voltage to be applied to the relay coil during the predetermined period from detection of occurrence of the abnormality to notification of the occurrence of the abnormality by the notification unit when the abnormality detection unit detects that the abnormality has occurred. an indoor unit; an outdoor unit; a relay circuit including a contact and a relay coil; a control unit to cause a first voltage equal to or higher than an operating voltage for turning ON the contact or a second voltage lower than the operating voltage and equal to or higher than a retention voltage for retaining a state in which the contact is ON to be applied to the relay coil; and one end portion of two end portions (4p, 4q) of the contact is connected to an alternating-current power supply and another end portion of the two end portions (4p, 4q) of the contact is connected to the outdoor unit, one end portion of two end portions (4x, 4y) of the relay coil is connected to a power supply for driving the relay circuit, and the control unit is configured to cause the first voltage to be applied to the relay coil at a start of an ON state of the contact, cause the second voltage to be applied to the relay coil after the contact is turned ON, characterized by further comprising an abnormality detection unit configured to, when an abnormality occurs in the outdoor unit, detect occurrence of the abnormality in the outdoor unit, and the indoor unit including a notification unit configured to, when the abnormality detection unit detects that an abnormality has occurred in the outdoor unit, notify that the abnormality has occurred in the outdoor unit after confirming that the abnormality occurring in the outdoor unit has continued for a predetermined period, the control unit being configured to cause the first voltage to be applied to the relay coil during the predetermined period from detection of occurrence of the abnormality to notification of the occurrence of the abnormality by the notification unit when the abnormality detection unit detects that the abnormality has occurred.