A component mounter comprising: a mounting head which has a rotating body and multiple holding bodies arranged along a circumferential direction of the rotating body and is configured to hold a component, the multiple holding bodies revolving along a revolution trajectory caused by rotation of the rotating body, a component pickup position, where the holding bodies are adapted to pick up a component, residing on the revolution trajectory; a revolving mechanism configured to revolve the multiple holding bodies by rotating the rotating body; a rotating mechanism configured to cause the multiple holding bodies to rotate respectively in synchronism with each other; a detection section configured to detect, from a side thereof, a component being held by the holding body that is located in a component detection position which is different from the component pickup position on the revolution trajectory, and a control section configured to perform component pickup processing and holding body revolving processing alternately and repeatedly, the component pickup processing causing the mounting head to enable the holding body that is located in the component pickup position to pick up and hold a component, the holding body revolving processing causing the revolving mechanism to locate, in the component pickup position, a holding body that does not hold a component, characterized by the control section further configured to, when performing the holding body revolving processing, perform holding body rotating processing, which causes the rotating mechanism to change a component holding angle of a component held to a holding body located in the component detection position through the current holding body revolving processing to a detection angle that differs from the component holding angle of the component when the component was picked up, the component holding angle representing an orientation of the component based on a radial direction of the revolution trajectory. a mounting head which has a rotating body and multiple holding bodies arranged along a circumferential direction of the rotating body and is configured to hold a component, the multiple holding bodies revolving along a revolution trajectory caused by rotation of the rotating body, a component pickup position, where the holding bodies are adapted to pick up a component, residing on the revolution trajectory; a revolving mechanism configured to revolve the multiple holding bodies by rotating the rotating body; a rotating mechanism configured to cause the multiple holding bodies to rotate respectively in synchronism with each other; a detection section configured to detect, from a side thereof, a component being held by the holding body that is located in a component detection position which is different from the component pickup position on the revolution trajectory, and a control section configured to perform component pickup processing and holding body revolving processing alternately and repeatedly, the component pickup processing causing the mounting head to enable the holding body that is located in the component pickup position to pick up and hold a component, the holding body revolving processing causing the revolving mechanism to locate, in the component pickup position, a holding body that does not hold a component, characterized by the control section further configured to, when performing the holding body revolving processing, perform holding body rotating processing, which causes the rotating mechanism to change a component holding angle of a component held to a holding body located in the component detection position through the current holding body revolving processing to a detection angle that differs from the component holding angle of the component when the component was picked up, the component holding angle representing an orientation of the component based on a radial direction of the revolution trajectory.