A mounting device comprising: a mounting head, having a rotating body, which turns multiple pickup members by rotating the rotating body, in which the rotating body holds multiple pickup members, each of which being configured to pick up a component, the multiple pickup members being disposed at predetermined intervals along a predetermined circumference of the rotating body; a moving section configured to move the mounting head; and a control section executing a forward rotation pickup processing of causing the pickup members to pick up the components from a supply section for supplying the components, and rotates the rotating body forwards, and while, when at least one of the pickup members is vacant resulting from an error of not holding the component, the control section executing a backward rotation pickup processing which includes a processing of causing the rotating body to rotate backwards and a processing of causing the vacant pickup member to pick up the component from the supply section, wherein the mounting device comprises a detecting section configured to detect a situation in which the pickup member, which is caused to pick up the component, does not hold the component as the error, and wherein the control section determines whether the vacant pickup member exists based on the error from the detecting section wherein the supply section comprises a component holding member configured to hold the component and a replenishment component holding member configured to hold the component, and wherein, when the vacant pickup member is generated continuously a predetermined number of times when causing the mounting head to pick up the component from the component holding member, the control section detects a component shortage in the component holding member in question as the error and, in the event that the replenishment component holding member is provided, the control section executes the backward rotation pickup processing in which the mounting head is caused to pick up the component from the replenishment component holding member. a mounting head, having a rotating body, which turns multiple pickup members by rotating the rotating body, in which the rotating body holds multiple pickup members, each of which being configured to pick up a component, the multiple pickup members being disposed at predetermined intervals along a predetermined circumference of the rotating body; a moving section configured to move the mounting head; and a control section executing a forward rotation pickup processing of causing the pickup members to pick up the components from a supply section for supplying the components, and rotates the rotating body forwards, and while, when at least one of the pickup members is vacant resulting from an error of not holding the component, the control section executing a backward rotation pickup processing which includes a processing of causing the rotating body to rotate backwards and a processing of causing the vacant pickup member to pick up the component from the supply section, wherein the mounting device comprises a detecting section configured to detect a situation in which the pickup member, which is caused to pick up the component, does not hold the component as the error, and wherein the control section determines whether the vacant pickup member exists based on the error from the detecting section wherein the supply section comprises a component holding member configured to hold the component and a replenishment component holding member configured to hold the component, and wherein, when the vacant pickup member is generated continuously a predetermined number of times when causing the mounting head to pick up the component from the component holding member, the control section detects a component shortage in the component holding member in question as the error and, in the event that the replenishment component holding member is provided, the control section executes the backward rotation pickup processing in which the mounting head is caused to pick up the component from the replenishment component holding member.