A component mounting device, comprising: a component transfer device configured to hold a supplied component and mount the component on a conveyed board, an imaging device (40, 50) configured to image the component or the board, and a control device configured to control the component transfer device; the control device including: a model data storage section configured to store model data produced based on information about the component and indicating the outer shape of the component; an error determining section configured to determine whether a processing error has occurred in a series of processes from the start of the holding operation of the component to the completion of mounting, and a confirmation-necessity storage section configured to store information about whether confirmation of validity of the model data is not verified up to the moment the processing error occurred and therefore is necessary in case a processing error has occurred in the series of processes performed based on each piece of model data stored in the model data storage section, characterized in that: when the error determining section determined that the processing error has occurred, in a case the confirmation-necessity storage section is indicating that confirmation of validity is necessary for the model data, which is related to the target component held by the component transfer device the control device is configured to temporarily suspend the mounting operation by the component transfer device, or in a case of the model data stored in the confirmation-necessity storage section indicating that confirmation of validity is unnecessary, to continue the mounting operation by the component transfer device. a component transfer device configured to hold a supplied component and mount the component on a conveyed board, an imaging device (40, 50) configured to image the component or the board, and a control device configured to control the component transfer device; the control device including: a model data storage section configured to store model data produced based on information about the component and indicating the outer shape of the component; an error determining section configured to determine whether a processing error has occurred in a series of processes from the start of the holding operation of the component to the completion of mounting, and a confirmation-necessity storage section configured to store information about whether confirmation of validity of the model data is not verified up to the moment the processing error occurred and therefore is necessary in case a processing error has occurred in the series of processes performed based on each piece of model data stored in the model data storage section, characterized in that: when the error determining section determined that the processing error has occurred, in a case the confirmation-necessity storage section is indicating that confirmation of validity is necessary for the model data, which is related to the target component held by the component transfer device the control device is configured to temporarily suspend the mounting operation by the component transfer device, or in a case of the model data stored in the confirmation-necessity storage section indicating that confirmation of validity is unnecessary, to continue the mounting operation by the component transfer device. a model data storage section configured to store model data produced based on information about the component and indicating the outer shape of the component; an error determining section configured to determine whether a processing error has occurred in a series of processes from the start of the holding operation of the component to the completion of mounting, and a confirmation-necessity storage section configured to store information about whether confirmation of validity of the model data is not verified up to the moment the processing error occurred and therefore is necessary in case a processing error has occurred in the series of processes performed based on each piece of model data stored in the model data storage section, characterized in that: when the error determining section determined that the processing error has occurred, in a case the confirmation-necessity storage section is indicating that confirmation of validity is necessary for the model data, which is related to the target component held by the component transfer device the control device is configured to temporarily suspend the mounting operation by the component transfer device, or in a case of the model data stored in the confirmation-necessity storage section indicating that confirmation of validity is unnecessary, to continue the mounting operation by the component transfer device.