An image forming device includes a communicator that receives a series of image data, a timer that measures a reception time of each of the series of image data, and a storage that temporarily stores the image data received before forming an image based on the series of image data. When the communicator receives image data, and subsequently does not receive the next image data within a predetermined reception time, the controller obtains the time difference between the time of the reception end of the series of image data, and the reception time of the image data last received by the communicator, determines that the last received image data may be incomplete image data when the time difference is greater than or equal to a predetermined time, and determines whether to form an image based on the image data stored in the storage according to the determination.